Factor out 'test invalid' checks

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@4837 9d0c8265-081b-0410-96cb-a4ca84ce46f8

53 files changed, 506 insertions, 1832 deletions

diff --git a/test/Execute-Tests b/test/Execute-Tests
index 3c231d98..c86121dc 100755
--- a/test/Execute-Tests
+++ b/test/Execute-Tests
@@ -50,7 +50,7 @@ esac
 # invoke, the list of tests to run ('Test-Order'), and *.ok files that
 # indicate the expected results of tests.
 
-srcdir=$(dirname $0)
+export srcdir=$(dirname $0)
 
 # Set tmpdir, which is used in some of the test scripts.  By default
 # this is created by mktemp.  The user can override and specify tmpdir,
diff --git a/test/pamarith.test b/test/pamarith.test
index 03ce7317..20c4039d 100755
--- a/test/pamarith.test
+++ b/test/pamarith.test
@@ -116,142 +116,68 @@ for image in maze.pbm ${input1_ppm}
 
 rm ${input1_ppm}
 
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
+. ${srcdir}/test-invalid.inc
 
 # multiple functions
 
-pamarith -add -subtract testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -multiply -divide testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -difference -minimum testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -maximum -mean testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -compare -and testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -compare -equal testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -or -nand testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -nor -xor testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -shiftleft -shiftright testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -add -subtract testimg.ppm testimg.ppm"
+invCmd "pamarith -multiply -divide testimg.ppm testimg.ppm"
+invCmd "pamarith -difference -minimum testimg.ppm testimg.ppm"
+invCmd "pamarith -maximum -mean testimg.ppm testimg.ppm"
+invCmd "pamarith -compare -and testimg.ppm testimg.ppm"
+invCmd "pamarith -compare -equal testimg.ppm testimg.ppm"
+invCmd "pamarith -or -nand testimg.ppm testimg.ppm"
+invCmd "pamarith -nor -xor testimg.ppm testimg.ppm"
+invCmd "pamarith -shiftleft -shiftright testimg.ppm testimg.ppm"
 
 # -add does not take a value
 
-pamarith -add=1 testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -add=1 testimg.ppm testimg.ppm"
 
 # No function
 
-pamarith -plain testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -plain testimg.ppm testimg.ppm"
+invCmd "pamarith testimg.ppm testimg.ppm"
 
 # Just one input image file
 
-pamarith -add testimg.ppm > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -add testimg.ppm"
 
 # No input image file
 
-pamarith -add > ${test_out} || \
-  printf "Expected failure 14 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -add"
 
 # Input images with different depth (number of planes)
 
-pamchannel -infile testimg.ppm 0 1 | \
-  pamarith -add testimg.ppm - > ${test_out} || \
-  printf "Expected failure 15 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+input1_pam=${tmpdir}/input1.pam
 
-# Input images with different x/y dimensions
+pamchannel -infile testimg.ppm 0 1 > ${input1_pam}
+invCmd "pamarith -add testimg.ppm ${input1_pam}"
+rm ${input1_pam}
 
-pamarith -add testimg.ppm testgrid.pbm > ${test_out} || \
-  printf "Expected failure 16 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamenlarge -xscale=2 testgrid.pbm | \
-  pamarith -add testgrid.pbm - > ${test_out} || \
-  printf "Expected failure 17 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+# Input images with different x/y dimensions
 
-pamenlarge -yscale=3 testgrid.pbm | \
-  pamarith -add testgrid.pbm - > ${test_out} || \
-  printf "Expected failure 18 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -add testimg.ppm testgrid.pbm"
 
-# Invalid usage of -closeness
+input1_pbm=${tmpdir}/input1.pbm
+input2_pbm=${tmpdir}/input2.pbm
 
-pamarith -equal -closeness=100.1 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 19 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+pamenlarge -xscale=2 testgrid.pbm > ${input1_pbm}
+invCmd "pamarith -add testgrid.pbm ${input1_pbm}"
+rm ${input1_pbm}
 
-pamarith -equal -closeness=-10 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 20 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+pamenlarge -yscale=3 testgrid.pbm > ${input2_pbm}
+invCmd "pamarith -add testgrid.pbm ${input2_pbm}"
+rm ${input2_pbm}
 
-pamarith -closeness -equal testgrid.pbm > ${test_out} || \
-  printf "Expected failure 21 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+# Invalid usage of -closeness
 
-pamarith -compare -closeness=10 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 22 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -equal -closeness=100.1 testgrid.pbm"
+invCmd "pamarith -equal -closeness=-10 testgrid.pbm"
+invCmd "pamarith -closeness -equal testgrid.pbm"
+invCmd "pamarith -compare -closeness=10 testgrid.pbm"
 
 # Bit string functions
 # Create PGM test input
@@ -266,67 +192,21 @@ pgmmake -maxval=8191 1.0 3 1 > ${input5_pgm}
 
 # Bit string functions - Maxval must match
 
-pamarith -and ${input3_pgm} ${input5_pgm} > ${test_out} || \
-  printf "Expected failure 23 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -or ${input3_pgm} ${input5_pgm} > ${test_out} || \
-  printf "Expected failure 24 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -nand ${input3_pgm} ${input5_pgm} > ${test_out} || \
-  printf "Expected failure 25 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -nor ${input3_pgm} ${input5_pgm} > ${test_out} || \
-  printf "Expected failure 26 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -xor ${input3_pgm} ${input5_pgm} > ${test_out} || \
-  printf "Expected failure 27 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -and ${input3_pgm} ${input5_pgm}"
+invCmd "pamarith -or ${input3_pgm} ${input5_pgm}"
+invCmd "pamarith -nand ${input3_pgm} ${input5_pgm}"
+invCmd "pamarith -nor ${input3_pgm} ${input5_pgm}"
+invCmd "pamarith -xor ${input3_pgm} ${input5_pgm}"
 
 # Bit string functions - Maxval must be 2^n -1
 
-pamarith -and ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 28 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -or ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 29 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -nand ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 30 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -nor ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 31 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -xor ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 32 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -shiftleft ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 33 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -shiftright ${input4_pgm} ${input4_pgm} > ${test_out} || \
-  printf "Expected failure 34 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -and ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -or ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -nand ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -nor ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -xor ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -shiftleft ${input4_pgm} ${input4_pgm}"
+invCmd "pamarith -shiftright ${input4_pgm} ${input4_pgm}"
 
 rm ${input3_pgm} ${input4_pgm} ${input5_pgm}
 
@@ -334,45 +214,15 @@ rm ${input3_pgm} ${input4_pgm} ${input5_pgm}
 # Only the functions that are commutative and associative allow
 # three or more inputs.
 
-pamarith -subtract testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 35 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -divide testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 36 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -compare testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 37 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -difference testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 38 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -shiftleft testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 39 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -shiftright testimg.ppm testimg.ppm testimg.ppm > ${test_out} || \
-  printf "Expected failure 40 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -subtract testimg.ppm testimg.ppm testimg.ppm"
+invCmd "pamarith -divide testimg.ppm testimg.ppm testimg.ppm"
+invCmd "pamarith -compare testimg.ppm testimg.ppm testimg.ppm"
+invCmd "pamarith -difference testimg.ppm testimg.ppm testimg.ppm"
+invCmd "pamarith -shiftleft testimg.ppm testimg.ppm testimg.ppm"
+invCmd "pamarith -shiftright testimg.ppm testimg.ppm testimg.ppm"
 
 # Currently -equal and -mean do not allow more than two input images.
 # These two cases should be removed once improvements are made.
 
-pamarith -equal testgrid.pbm testgrid.pbm testgrid.pbm > ${test_out} || \
-  printf "Expected failure 41 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamarith -mean testgrid.pbm  testgrid.pbm testgrid.pbm > ${test_out} || \
-  printf "Expected failure 42 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamarith -equal testgrid.pbm testgrid.pbm testgrid.pbm"
+invCmd "pamarith -mean testgrid.pbm  testgrid.pbm testgrid.pbm"
diff --git a/test/pambrighten.ok b/test/pambrighten.ok
index 6c58b4c9..8dc9e71e 100644
--- a/test/pambrighten.ok
+++ b/test/pambrighten.ok
@@ -78,19 +78,11 @@ Test 4: Should print 3990234518 268 six times
 3990234518 268
 3990234518 268
 3990234518 268
-Test Error: Should print 1 six times
-1
-1
-1
-1
-1
-1
-Test Error: Should print 99 followed by 1, four times
-99
-1
-99
-1
-99
-1
-99
-1
+Test Invalid
+Expected failure 1 (no output)
+Expected failure 2 (no output)
+Expected failure 3 (no output)
+Expected failure 4 (no output)
+Expected failure 5 (no output)
+Expected failure 6 (no output)
+Expected failure 7 (no output)
diff --git a/test/pambrighten.test b/test/pambrighten.test
index 00e405dd..d79ad583 100755
--- a/test/pambrighten.test
+++ b/test/pambrighten.test
@@ -10,7 +10,7 @@ cat > ${input_ppm} << EOF
 P3
 8 1
 255
-0 0 0 0 0 100 0 100 0 0 100 100 100 0 0 100 0 100 100 100 0 100 100 100 
+0 0 0 0 0 100 0 100 0 0 100 100 100 0 0 100 0 100 100 100 0 100 100 100
 EOF
 
 # Test 1
@@ -50,50 +50,14 @@ pambrighten -s +200 ${input_pgm} | cksum
 
 rm ${input_pgm}
 
+echo "Test Invalid"
 
-# Test 2
-# These should all fail.
+. ${srcdir}/test-invalid.inc
 
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-echo "Test Error: Should print 1 six times"
-
-output_ppm=${tmpdir}/output.ppm
-
-pambrighten -v -120 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten -s -120 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten 10 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-
-
-echo "Test Error: Should print 99 followed by 1, four times"
-
-pambrighten -s 1.20 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten -v 10.5 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten -v testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten -s testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-
-
-rm -f ${output_ppm}
+invCmd "pambrighten -v -120 testimg.ppm"
+invCmd "pambrighten -s -120 testimg.ppm"
+invCmd "pambrighten 10 testimg.ppm"
+invCmd "pambrighten -s 1.20 testimg.ppm"
+invCmd "pambrighten -v 10.5 testimg.ppm"
+invCmd "pambrighten -v testimg.ppm"
+invCmd "pambrighten -s testimg.ppm"
diff --git a/test/pamcat1.test b/test/pamcat1.test
index 902ef6d7..9480228c 100755
--- a/test/pamcat1.test
+++ b/test/pamcat1.test
@@ -187,82 +187,26 @@ rm ${seq2_4h_pam} ${seq2_4v_pam} ${seq2_4v3_pam} ${seq2_4h4_pam}
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
 # direction not specified
-pamcat testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcat testgrid.pbm testimg.ppm"
 
 # both directions specified
-pamcat -topbottom -leftright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcat -topbottom -leftright testgrid.pbm testimg.ppm"
 
 # both pad colors specified
-pamcat -topbottom -white -black testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-# justification parameters overspecified
-pamcat -lr -jtop -jbottom testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -lr -jtop -jcenter testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -lr -jcenter -jbottom testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -tb -jleft -jright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -tb -jleft -jcenter testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -tb -jcenter -jright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-# justification parameter in the wrong direction
-pamcat -lr -jleft    testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -lr -jright   testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -tb -jtop     testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcat -tb -jbottom  testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcat -topbottom -white -black testgrid.pbm testimg.ppm"
+invCmd "pamcat -lr -jtop -jbottom testgrid.pbm testimg.ppm"
+invCmd "pamcat -lr -jtop -jcenter testgrid.pbm testimg.ppm"
+invCmd "pamcat -lr -jcenter -jbottom testgrid.pbm testimg.ppm"
+invCmd "pamcat -tb -jleft -jright testgrid.pbm testimg.ppm"
+invCmd "pamcat -tb -jleft -jcenter testgrid.pbm testimg.ppm"
+invCmd "pamcat -tb -jcenter -jright testgrid.pbm testimg.ppm"
+invCmd "pamcat -lr -jleft    testgrid.pbm testimg.ppm"
+invCmd "pamcat -lr -jright   testgrid.pbm testimg.ppm"
+invCmd "pamcat -tb -jtop     testgrid.pbm testimg.ppm"
+invCmd "pamcat -tb -jbottom  testgrid.pbm testimg.ppm"
 
 # more than one input image from standard input
 cat testgrid.pbm | pamcat -lr - - testimg.ppm > ${test_out} || \
diff --git a/test/pamchannel.test b/test/pamchannel.test
index 2f772bf9..f3399343 100755
--- a/test/pamchannel.test
+++ b/test/pamchannel.test
@@ -41,17 +41,8 @@ test_out=${tmpdir}/test_out
 
 echo "Test Invalid"
 
-pamchannel  -infile testgrid.pbm 1 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamchannel  -infile testimg.ppm 3 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamtopam testimg.ppm | pamchannel -infile=- 4 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamchannel  -infile testgrid.pbm 1"
+invCmd "pamchannel  -infile testimg.ppm 3"
+invCmd "pamtopam testimg.ppm | pamchannel -infile=- 4"
diff --git a/test/pamcrater.test b/test/pamcrater.test
index 1b4ffd54..5362bde3 100755
--- a/test/pamcrater.test
+++ b/test/pamcrater.test
@@ -52,33 +52,17 @@ pamshadedrelief ${test100_pam} > ${testshaded_pam}
   pamcut -top=$((128 - 99)) -height=1  ${testshaded_pam} | cksum
 ) | uniq -c | awk '{print $1}'
 
-rm ${testshaded_pam} ${test100_pam} ${test150_pam}
+rm ${testshaded_pam} ${test150_pam}
 
 echo "Test Invalid."
 
 test_out=${tmpdir}/test_out
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "------------------------------" 1>&2
-
-pamcrater -width 0 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcrater -height 0 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcrater -number 0 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcrater -test -radius=10 | pamshadedrelief -gamma 0 > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamcrater -width 0"
+invCmd "pamcrater -height 0"
+invCmd "pamcrater -number 0"
+invCmd "pamshadedrelief -gamma 0 ${test100_pam}"
+
+rm ${test100_pam}
diff --git a/test/pamcut.ok b/test/pamcut.ok
index 60919865..3c490427 100644
--- a/test/pamcut.ok
+++ b/test/pamcut.ok
@@ -28,9 +28,9 @@ Expected failure 6 (no output)
 Expected failure 7 (no output)
 Expected failure 8 (no output)
 Expected failure 9 (no output)
-Expected failure 6 (no output)
 Expected failure 10 (no output)
 Expected failure 11 (no output)
 Expected failure 12 (no output)
 Expected failure 13 (no output)
 Expected failure 14 (no output)
+Expected failure 15 (no output)
diff --git a/test/pamcut.test b/test/pamcut.test
index 7cda5bce..7cbabf51 100755
--- a/test/pamcut.test
+++ b/test/pamcut.test
@@ -30,7 +30,7 @@ echo "Test 5. Should print 281226646 481 five times"
 mazesize=$(pamfile -size maze.pbm)
 width=$(echo ${mazesize} | cut -d " " -f 1)
 height=$(echo ${mazesize} | cut -d " " -f 2)
- 
+
 pamcut -croptop 0 -cropleft 0 -cropbottom 0 -cropright 0 maze.pbm | \
   cksum
 pamcut -top 0 -left 0 -bottom $((${height} -1)) -right $((${width} -1)) \
@@ -38,7 +38,7 @@ pamcut -top 0 -left 0 -bottom $((${height} -1)) -right $((${width} -1)) \
 pamcut -top 0 -left 0 -bottom -1 -right -1 maze.pbm | cksum
 pamcut -top 0 -left 0 -width ${width} -height ${height} maze.pbm | cksum
 pamcut maze.pbm | cksum
- 
+
 echo "Test 6.  Should print 3412257956 129"
 
 pbmmake -g 50 50 | pamcut 5 5 30 30 | cksum
@@ -46,89 +46,25 @@ pbmmake -g 50 50 | pamcut 5 5 30 30 | cksum
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
 # overspecification
-pamcut -left=1 -right=1 -width=14 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -top=1 -bottom=1 -height=16 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -right=1 -cropright=1 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -top=1 -croptop=1 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -bottom=1 -cropbottom=1 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -left=1 -cropleft=1 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-# excessive cropping
-pamcut -cropleft=7 -cropright=8 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -left=7 -right=6 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -croptop=8 -cropbottom=8 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -top=10 -bottom=9 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcut -left=1 -right=1 -width=14 testgrid.pbm"
+invCmd "pamcut -top=1 -bottom=1 -height=16 testgrid.pbm"
+invCmd "pamcut -right=1 -cropright=1 testgrid.pbm"
+invCmd "pamcut -top=1 -croptop=1 testgrid.pbm"
+invCmd "pamcut -bottom=1 -cropbottom=1 testgrid.pbm"
+invCmd "pamcut -left=1 -cropleft=1 testgrid.pbm"
+invCmd "pamcut -cropleft=7 -cropright=8 testgrid.pbm"
+invCmd "pamcut -left=7 -right=6 testgrid.pbm"
+invCmd "pamcut -croptop=8 -cropbottom=8 testgrid.pbm"
+invCmd "pamcut -top=10 -bottom=9 testgrid.pbm"
 
 # pad absent
-pamcut -cropleft=1 -width=14 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut -croptop=1  -height=16 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcut -cropleft=1 -width=14 testgrid.pbm"
+invCmd "pamcut -croptop=1  -height=16 testgrid.pbm"
 
 # legacy style: insufficient number of positional parameters
-pamcut 5 testimg.ppm > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut 5 4 testimg.ppm > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamcut 5 5 30 testimg.ppm > ${test_out} || \
-  printf "Expected failure 14 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamcut 5 testimg.ppm"
+invCmd "pamcut 5 4 testimg.ppm"
+invCmd "pamcut 5 5 30 testimg.ppm"
diff --git a/test/pamdepth.test b/test/pamdepth.test
index d97992a1..e938a630 100755
--- a/test/pamdepth.test
+++ b/test/pamdepth.test
@@ -24,17 +24,7 @@ pamdepth 255 testimg.ppm | cmp -s - testimg.ppm
 # Test Invalid
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-pamdepth 0 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamdepth 65536 testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamdepth 0 testgrid.pbm"
+invCmd "pamdepth 65536 testimg.ppm"
diff --git a/test/pamditherbw.test b/test/pamditherbw.test
index ea3e803f..76bcdbd7 100755
--- a/test/pamditherbw.test
+++ b/test/pamditherbw.test
@@ -39,71 +39,19 @@ pamditherbw -cluster8 ${test_red} | cksum
 
 echo "Test: Invalid"
 
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamditherbw -fs -atkinson       ${test_red} > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -floyd -atkinson    ${test_red} > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -dither8  -cluster3 ${test_red} > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -cluster3 -cluster4 ${test_red} > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -cluster3 -cluster8 ${test_red} > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -cluster4 -cluster8 ${test_red} > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -hilbert -threshold ${test_red} > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -clump=8            ${test_red} > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -fs -clump=8        ${test_red} > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -hilbert -clump=1   ${test_red} > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -th -value=-1       ${test_red} > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamditherbw -th -value=1.1      ${test_red} > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamditherbw -fs -atkinson       ${test_red}"
+invCmd "pamditherbw -floyd -atkinson    ${test_red}"
+invCmd "pamditherbw -dither8  -cluster3 ${test_red}"
+invCmd "pamditherbw -cluster3 -cluster4 ${test_red}"
+invCmd "pamditherbw -cluster3 -cluster8 ${test_red}"
+invCmd "pamditherbw -cluster4 -cluster8 ${test_red}"
+invCmd "pamditherbw -hilbert -threshold ${test_red}"
+invCmd "pamditherbw -clump=8            ${test_red}"
+invCmd "pamditherbw -fs -clump=8        ${test_red}"
+invCmd "pamditherbw -hilbert -clump=1   ${test_red}"
+invCmd "pamditherbw -th -value=-1       ${test_red}"
+invCmd "pamditherbw -th -value=1.1      ${test_red}"
 
 rm ${test_red}
diff --git a/test/pamfile.test b/test/pamfile.test
index 7be061ef..d605326d 100755
--- a/test/pamfile.test
+++ b/test/pamfile.test
@@ -22,25 +22,13 @@ cat testgrid.pbm testimg.ppm testgrid.pbm | pamfile -machine
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamfile -size -machine  testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfile -count -machine testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-head -n1 testimg.ppm | pamfile > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamfile -size -machine  testimg.ppm"
+invCmd "pamfile -count -machine testimg.ppm"
+
+head1_ppm=${tmpdir}/head1.ppm
+
+head -n1 testimg.ppm > ${head1_ppm}
+invCmd "pamfile  ${head1_ppm}"
+rm ${head1_ppm}
diff --git a/test/pamfind.test b/test/pamfind.test
index e7c9707f..079e35f4 100755
--- a/test/pamfind.test
+++ b/test/pamfind.test
@@ -31,34 +31,11 @@ comm -12 ${sorted0_res}  ${sorted1_res} |
 
 rm ${sorted0_res} ${sorted1_res}
 
-# Test 4
-
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
 echo "Test Invalid"
 
-pamfind -color=black -target=1,1,1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfind -target=0,0 testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfind -target=0,0,0,0 testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
 
-pamfind testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamfind -color=black -target=1,1,1 testimg.ppm"
+invCmd "pamfind -target=0,0 testimg.ppm"
+invCmd "pamfind -target=0,0,0,0 testimg.ppm"
+invCmd "pamfind testimg.ppm"
diff --git a/test/pamfunc.test b/test/pamfunc.test
index 21f69247..b1b9edfc 100755
--- a/test/pamfunc.test
+++ b/test/pamfunc.test
@@ -84,130 +84,32 @@ pamfunc -xormask  0x1 maze.pbm | pamfunc -xormask 0x1 | cksum
 pamfunc -shiftleft  0 maze.pbm | cksum
 pamfunc -shiftright 0 maze.pbm | cksum
 
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
-
-pamfunc -multiplier testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -multiplier=-1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -divisor testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -divisor=-20 testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -adder testimg.ppm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -adder 0.5 testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -subtractor testimg.ppm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -subtractor 0.1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -multiplier=1 -divisor=2 testimg.ppm > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -adder=2 -subtractor=3 testimg.ppm > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -min testimg.ppm > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -max testimg.ppm > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -andmask testimg.ppm > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -ormask testimg.ppm > ${test_out} || \
-  printf "Expected failure 14 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -xormask testimg.ppm > ${test_out} || \
-  printf "Expected failure 15 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -not 1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 16 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -min=1 -max=2 testimg.ppm > ${test_out} || \
-  printf "Expected failure 17 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -andmask=1 -ormask=0 testimg.ppm > ${test_out} || \
-  printf "Expected failure 18 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -andmask=0xffff testimg.ppm > ${test_out} || \
-  printf "Expected failure 19 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -shiftleft testimg.ppm > ${test_out} || \
-  printf "Expected failure 20 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -shiftright testimg.ppm > ${test_out} || \
-  printf "Expected failure 21 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -changemaxval testimg.ppm > ${test_out} || \
-  printf "Expected failure 22 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -shiftleft=1 -shiftright=1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 23 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamfunc -multiplier=0.5 -changemaxval=65535 testimg.ppm > ${test_out} || \
-  printf "Expected failure 24 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamfunc -multiplier testimg.ppm"
+invCmd "pamfunc -multiplier=-1 testimg.ppm"
+invCmd "pamfunc -divisor testimg.ppm"
+invCmd "pamfunc -divisor=-20 testimg.ppm"
+invCmd "pamfunc -adder testimg.ppm"
+invCmd "pamfunc -adder 0.5 testimg.ppm"
+invCmd "pamfunc -subtractor testimg.ppm"
+invCmd "pamfunc -subtractor 0.1 testimg.ppm"
+invCmd "pamfunc -multiplier=1 -divisor=2 testimg.ppm"
+invCmd "pamfunc -adder=2 -subtractor=3 testimg.ppm"
+invCmd "pamfunc -min testimg.ppm"
+invCmd "pamfunc -max testimg.ppm"
+invCmd "pamfunc -andmask testimg.ppm"
+invCmd "pamfunc -ormask testimg.ppm"
+invCmd "pamfunc -xormask testimg.ppm"
+invCmd "pamfunc -not 1 testimg.ppm"
+invCmd "pamfunc -min=1 -max=2 testimg.ppm"
+invCmd "pamfunc -andmask=1 -ormask=0 testimg.ppm"
+invCmd "pamfunc -andmask=0xffff testimg.ppm"
+invCmd "pamfunc -shiftleft testimg.ppm"
+invCmd "pamfunc -shiftright testimg.ppm"
+invCmd "pamfunc -changemaxval testimg.ppm"
+invCmd "pamfunc -shiftleft=1 -shiftright=1 testimg.ppm"
+invCmd "pamfunc -multiplier=0.5 -changemaxval=65535 testimg.ppm"
diff --git a/test/pamgauss.ok b/test/pamgauss.ok
index cc4d1465..98d97312 100644
--- a/test/pamgauss.ok
+++ b/test/pamgauss.ok
@@ -89,3 +89,6 @@ Expected failure 2 (no output)
 Expected failure 3 (no output)
 Expected failure 4 (no output)
 Expected failure 5 (no output)
+Expected failure 6 (no output)
+Expected failure 7 (no output)
+Expected failure 8 (no output)
diff --git a/test/pamgauss.test b/test/pamgauss.test
index b15ccbf0..34b6630a 100755
--- a/test/pamgauss.test
+++ b/test/pamgauss.test
@@ -19,35 +19,13 @@ pamgauss 3 3 -sigma=0.5 -tupletype="GRAYSCALE" | pamfile
 
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-pamgauss 3 3               > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamgauss 3 3   -sigma=0    > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamgauss 3 3   -sigma=-1.5 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamgauss 3     -sigma=0.5  > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamgauss 3 3 3 -sigma=0.5  > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamgauss       -sigma=0.5 "
+invCmd "pamgauss 0 5   -sigma=0.5 "
+invCmd "pamgauss 5 0   -sigma=0.5"
+invCmd "pamgauss 3 3              "
+invCmd "pamgauss 3 3   -sigma=0   "
+invCmd "pamgauss 3 3   -sigma=-1.5"
+invCmd "pamgauss 3     -sigma=0.5 "
+invCmd "pamgauss 3 3 3 -sigma=0.5 "
diff --git a/test/pamhue.test b/test/pamhue.test
index ca7a7d82..ce148a45 100755
--- a/test/pamhue.test
+++ b/test/pamhue.test
@@ -34,15 +34,6 @@ pamhue -huechange=360 testimg.ppm | cmp -s - testimg.ppm
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Omission of mandatory argument." 1>&2
-echo "An error message should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamhue testimg.ppm  > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamhue testimg.ppm "
diff --git a/test/pamrecolor.test b/test/pamrecolor.test
index 4d75f2cc..b5674776 100755
--- a/test/pamrecolor.test
+++ b/test/pamrecolor.test
@@ -16,47 +16,16 @@ echo "Test 2. Should produce 3500040755 101532 twice"
 pamrecolor --targetcolor=rgb:80/80/80 testimg.ppm | cksum
 pamrecolor --colorspace=ntsc --targetcolor=rgb:80/80/80 testimg.ppm | cksum
 
+. ${srcdir}/test-invalid.inc
 
-test_out=${tmpdir}/test_out
 truncated_file=${tmpdir}/truncated.txt
 echo P6 > ${truncated_file}
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamrecolor --targetcolor=rgb:00/11/22 \
-           --colorfile=${base1_pgm} testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrecolor --rmult=0.3  --gmult=0.3  --bmult=0.3 \
-           --colorfile=${base1_pgm} testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrecolor --colorspace=void \
-           --targetcolor=rgb:80/80/80 testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrecolor --targetcolor=vague testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrecolor --colorfile=${truncated_file} testimg.ppm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrecolor --rmult=0.2989 --gmult=0.5866 testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamrecolor --targetcolor=rgb:00/11/22 --colorfile=${base_pgm} testimg.ppm"
+invCmd "pamrecolor --rmult=0.3  --gmult=0.3  --bmult=0.3 --colorfile=${base_pgm} testimg.ppm"
+invCmd "pamrecolor --colorspace=void --targetcolor=rgb:80/80/80 testimg.ppm"
+invCmd "pamrecolor --targetcolor=vague testimg.ppm"
+invCmd "pamrecolor --colorfile=${truncated_file} testimg.ppm"
+invCmd "pamrecolor --rmult=0.2989 --gmult=0.5866 testimg.ppm"
 
 rm ${base_pgm} ${truncated_file}
diff --git a/test/pamrestack.test b/test/pamrestack.test
index 776fe91b..c91830e4 100755
--- a/test/pamrestack.test
+++ b/test/pamrestack.test
@@ -58,34 +58,10 @@ pamrestack \
 test_out=${tmpdir}/test_out
 echo "Test Invalid."
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamrestack testgrid.pbm maze.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrestack -abort \
-  -width=$((pixels * 2 + 1 )) maze.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrestack -crop \
-  -width=$((pixels * 2 + 1)) maze.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrestack -width=0 maze.pbm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamrestack -width maze.pbm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamrestack testgrid.pbm maze.pbm"
+invCmd "pamrestack -abort -width=$((pixels * 2 + 1 )) maze.pbm"
+invCmd "pamrestack -crop -width=$((pixels * 2 + 1)) maze.pbm"
+invCmd "pamrestack -width=0 maze.pbm"
+invCmd "pamrestack -width maze.pbm"
diff --git a/test/pamscale-reportonly.test b/test/pamscale-reportonly.test
index 2bf1030a..39745809 100755
--- a/test/pamscale-reportonly.test
+++ b/test/pamscale-reportonly.test
@@ -19,48 +19,13 @@ pamscale -reportonly -pixels=45000 testimg.ppm
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
+. ${srcdir}/test-invalid.inc
 
 # Expected failure cases
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamscale -reportonly -xsize=640 -ysize=400 -xscale=2 testimg.ppm > \
-  ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamscale -reportonly -xsize=640 -xscale=2 -yscale=3 testimg.ppm > \
-  ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamscale -reportonly -xsize=640 -ysize=400 -pixels=200000 testimg.ppm \
-  > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamscale -reportonly -xsize=640 -ysize=400 -xysize 640 400 testimg.ppm \
-  > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamscale -reportonly -xsize=640 -ysize=400 -xyfit  640 400 testimg.ppm \
-  > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamscale -reportonly -xsize=640 -ysize=400 -xyfill 640 400 testimg.ppm \
-  > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamscale -reportonly -xsize=640 -ysize=400 -xscale=2 testimg.ppm"
+invCmd "pamscale -reportonly -xsize=640 -xscale=2 -yscale=3 testimg.ppm"
+invCmd "pamscale -reportonly -xsize=640 -ysize=400 -pixels=200000 testimg.ppm"
+invCmd "pamscale -reportonly -xsize=640 -ysize=400 -xysize 640 400 testimg.ppm"
+invCmd "pamscale -reportonly -xsize=640 -ysize=400 -xyfit  640 400 testimg.ppm"
+invCmd "pamscale -reportonly -xsize=640 -ysize=400 -xyfill 640 400 testimg.ppm"
diff --git a/test/pamseq.test b/test/pamseq.test
index 61fbfac7..894e8d6d 100755
--- a/test/pamseq.test
+++ b/test/pamseq.test
@@ -8,35 +8,14 @@ pamseq 1 255 | cksum
 
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-pamseq 1 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamseq 0 255 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamseq 3 0   > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamseq 1"
+invCmd "pamseq 0 255"
+invCmd "pamseq 3 0"
 
+# Tupletype string length=256
 c64="0123456789012345678901234567890123456789012345678901234567890123"
 c256=${c64}${c64}${c64}${c64}
 
-# Tupletype string length=256
-
-pamseq -tupletype="${c256}" 3 15 > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamseq -tupletype=${c256} 3 15"
diff --git a/test/pamshuffle.test b/test/pamshuffle.test
index 700631cb..371b65a5 100755
--- a/test/pamshuffle.test
+++ b/test/pamshuffle.test
@@ -46,22 +46,8 @@ rm ${out1_pam}
 test_out=${tmpdir}/test_out
 echo "Test Invalid."
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-pamshuffle testimg.ppm testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamshuffle -randomseed -column testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamshuffle -randomseed=null testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamshuffle testimg.ppm testgrid.pbm"
+invCmd "pamshuffle -randomseed -column testgrid.pbm"
+invCmd "pamshuffle -randomseed=null testgrid.pbm"
diff --git a/test/pamstack.test b/test/pamstack.test
index 7c375b12..6374c4bd 100755
--- a/test/pamstack.test
+++ b/test/pamstack.test
@@ -93,33 +93,16 @@ s2=$(pamstack -firstmaxval ${std_pgm} | pamfile)
 
 test "$s0" = "$s1" && echo "true" || echo "false"
 test "$s0" = "$s2" && echo "true" || echo "false"
-  
+
 
 # Test Invalid
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-test_out=${tmpdir}/test_out
-
-pamstack testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamstack ${i1_pgm} ${std_pgm} > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
 
-pamstack -lcmmaxval -firstmaxval testgrid.pbm testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pamstack testgrid.pbm testimg.ppm"
+invCmd "pamstack ${i1_pgm} ${std_pgm}"
+invCmd "pamstack -lcmmaxval -firstmaxval testgrid.pbm testgrid.pbm"
 
-  
 rm ${i1_pgm} ${i2_pgm} ${i7_pgm} ${i31_pgm} ${std_pgm} ${max_pgm}
 
diff --git a/test/pamsumm.test b/test/pamsumm.test
index 6fef5972..eb41ee36 100755
--- a/test/pamsumm.test
+++ b/test/pamsumm.test
@@ -26,30 +26,9 @@ for type in -sum -min -max -mean
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pamsumm -sum -min  testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamsumm -sum -max  testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamsumm -mean -max testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pamsumm            testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pamsumm -sum -min  testimg.ppm"
+invCmd "pamsumm -sum -max  testimg.ppm"
+invCmd "pamsumm -mean -max testimg.ppm"
+invCmd "pamsumm            testimg.ppm"
diff --git a/test/pamtable.ok b/test/pamtable.ok
index 5d69ffb7..b63a74c2 100644
--- a/test/pamtable.ok
+++ b/test/pamtable.ok
@@ -122,5 +122,4 @@ Test 8
 65535     0     0|    0     0 65535|    0     0 65535|    0 65535     0
 
 Test Invalid
-Should print: Expected failure (no output)
-Expected failure (no output)
+Expected failure 1 (no output)
diff --git a/test/pamtable.test b/test/pamtable.test
index 740b2199..d42187f9 100755
--- a/test/pamtable.test
+++ b/test/pamtable.test
@@ -46,17 +46,10 @@ for maxval in 9 10 9999 10000 65535
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test.out
+. ${srcdir}/test-invalid.inc
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+input1_pam=${tmpdir}/input1.pam
 
-echo "Should print: Expected failure (no output)"
-
-pamseq -tupletype="void" 1 1 | pamtable -tuple -hex > \
-  ${test_out} || \
-  printf "Expected failure "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+pamseq -tupletype="void" 1 1 > ${input1_pam}
+invCmd "pamtable -tuple -hex ${input1_pam}"
+rm ${input1_pam}
diff --git a/test/pbmclean.test b/test/pbmclean.test
index 9d59a5a6..64ed6df0 100755
--- a/test/pbmclean.test
+++ b/test/pbmclean.test
@@ -37,17 +37,8 @@ rm ${sheet_pbm}
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combination." 1>&2
-echo "An error message should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
 # overspecification
-pbmclean -black -white -min=1 -extended testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
+invCmd "pbmclean -black -white -min=1 -extended testgrid.pbm"
 # note that without -extended the above is valid.
diff --git a/test/pbmmake.test b/test/pbmmake.test
index 52765747..32153f95 100755
--- a/test/pbmmake.test
+++ b/test/pbmmake.test
@@ -20,54 +20,17 @@ for size in 8 13 18 23 28 33 38 43 48 53 58 63 68 73 78 83 88 93 98
   ( pbmmake -w ${size} ${size} ;
     pbmmake -b ${size} ${size} ;
     pbmmake -g ${size} ${size} ) | cksum
-  done
+done
 
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-pbmmake -b -w -plain 1 1 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -b -g -plain 1 1 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -white -gray -plain 1 1 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -white -plain   > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -white -plain 1 > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -white -plain 1 0 > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmmake -white -plain 0 1 > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
 
-pbmmake -white -plain 1 1 1 > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pbmmake -b -w -plain 1 1"
+invCmd "pbmmake -b -g -plain 1 1"
+invCmd "pbmmake -white -gray -plain 1 1"
+invCmd "pbmmake -white -plain"
+invCmd "pbmmake -white -plain 1"
+invCmd "pbmmake -white -plain 1 0"
+invCmd "pbmmake -white -plain 0 1"
+invCmd 'pbmmake -white -plain 1 1 1'
diff --git a/test/pbmnoise-parameters.ok b/test/pbmnoise-parameters.ok
index d430f0f1..640b438d 100644
--- a/test/pbmnoise-parameters.ok
+++ b/test/pbmnoise-parameters.ok
@@ -16,7 +16,6 @@ Expected failure 14 (no output)
 Expected failure 15 (no output)
 Expected failure 16 (no output)
 Expected failure 17 (no output)
-Expected failure 17 (no output)
 Expected failure 18 (no output)
 Expected failure 19 (no output)
 Expected failure 20 (no output)
@@ -24,3 +23,6 @@ Expected failure 21 (no output)
 Expected failure 22 (no output)
 Expected failure 23 (no output)
 Expected failure 24 (no output)
+Expected failure 25 (no output)
+Expected failure 26 (no output)
+Expected failure 27 (no output)
diff --git a/test/pbmnoise-parameters.test b/test/pbmnoise-parameters.test
index 0d9319cc..d0e04ebf 100755
--- a/test/pbmnoise-parameters.test
+++ b/test/pbmnoise-parameters.test
@@ -2,142 +2,42 @@
 # This script tests: pbmnoise
 # Also requires:
 
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
+. ${srcdir}/test-invalid.inc
 
 # Invalid -ratio arguments
 
-pbmnoise -ratio       100 100 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio 0     1  100 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=1.1   100 100 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-  
-pbmnoise -ratio=-1    100 100 > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=half  100 100 > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=0/1/1 100 100 > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=-1/2  100 100 > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=1/0   100 100 > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=/2    100 100 > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=4/2   100 100 > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=6/    100 100 > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=1.0/2.0 100 100 > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-# denominator must be power of 2  
-pbmnoise -ratio=3/9   100 100 > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=a/2   100 100 > ${test_out} || \
-  printf "Expected failure 14 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-
-pbmnoise -ratio=2/a  100 100 > ${test_out} || \
-        printf "Expected failure 15 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=1/-2  100 100 > ${test_out} || \
-        printf "Expected failure 16 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pbmnoise -ratio       100 100"
+invCmd "pbmnoise -ratio 0     1  100"
+invCmd "pbmnoise -ratio=1.1   100 100"
+invCmd "pbmnoise -ratio=-1    100 100"
+invCmd "pbmnoise -ratio=half  100 100"
+invCmd "pbmnoise -ratio=0/1/1 100 100"
+invCmd "pbmnoise -ratio=-1/2  100 100"
+invCmd "pbmnoise -ratio=1/0   100 100"
+invCmd "pbmnoise -ratio=/2    100 100"
+invCmd "pbmnoise -ratio=4/2   100 100"
+invCmd "pbmnoise -ratio=6/    100 100"
+invCmd "pbmnoise -ratio=1.0/2.0 100 100"
+
+# denominator must be power of 2
+invCmd "pbmnoise -ratio=3/9  100 100"
+invCmd "pbmnoise -ratio=a/2  100 100"
+invCmd "pbmnoise -ratio=2/a  100 100"
+invCmd "pbmnoise -ratio=1/-2 100 100"
 
 # Denominator must be 65536 or less
-pbmnoise -ratio=1/65537 100 100 > ${test_out} || \
-  printf "Expected failure 17 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -ratio=1/131072 100 100 > ${test_out} || \
-  printf "Expected failure 17 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -endian=large 100 100 > ${test_out} || \
-  printf "Expected failure 18 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -randomseed 100 100 > ${test_out} || \
-  printf "Expected failure 19 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -randomseed=-1 100 100 > ${test_out} || \
-  printf "Expected failure 20 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise -randomseed=0.1 100 100 > ${test_out} || \
-  printf "Expected failure 21 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise > ${test_out} || \
-  printf "Expected failure 22 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise 100 > ${test_out} || \
-  printf "Expected failure 23 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmnoise 100 200 300 > ${test_out} || \
-  printf "Expected failure 24 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-  
+invCmd "pbmnoise -ratio=1/65537 100 100"
+invCmd "pbmnoise -ratio=1/131072 100 100"
+
+# Other
+invCmd "pbmnoise"
+invCmd "pbmnoise 100"
+invCmd "pbmnoise 100 0"
+invCmd "pbmnoise 0 100"
+invCmd "pbmnoise 100 200 300"
+invCmd "pbmnoise -endian=large 100 100"
+invCmd "pbmnoise -randomseed 100 100"
+invCmd "pbmnoise -randomseed=-1 100 100"
+invCmd "pbmnoise -randomseed=0.1 100 100"
diff --git a/test/pbmpage.test b/test/pbmpage.test
index ee3dc25c..9cb46e22 100755
--- a/test/pbmpage.test
+++ b/test/pbmpage.test
@@ -11,25 +11,9 @@ pbmpage -a4 2 | cksum
 
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
+invCmd "pbmpage -a3 1"
+invCmd "pbmpage 0"
+invCmd "pbmpage 4"
 
-pbmpage -a3 1 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmpage 0 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmpage 4 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
diff --git a/test/pbmpscale.test b/test/pbmpscale.test
index 65ab6467..b99561f6 100755
--- a/test/pbmpscale.test
+++ b/test/pbmpscale.test
@@ -25,27 +25,10 @@ pbmtext -nomargin "9" | pbmpscale 9 | cksum
 echo "Test 10. Should print 3327221668 2111"
 pbmtext -nomargin "10" | pbmpscale 10 | cksum
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pbmpscale testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmpscale 0 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
 
-pbmpscale 2 3 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pbmpscale testgrid.pbm"
+invCmd "pbmpscale 0 testgrid.pbm"
+invCmd "pbmpscale 2 3 testgrid.pbm"
diff --git a/test/pbmtopgm.test b/test/pbmtopgm.test
index f2c5cf1f..19378bb6 100755
--- a/test/pbmtopgm.test
+++ b/test/pbmtopgm.test
@@ -9,30 +9,9 @@ pbmtopgm -plain 1 1 testgrid.pbm
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
+. ${srcdir}/test-invalid.inc
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pbmtopgm 5 0 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmtopgm 0 9 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmtopgm 15 5 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pbmtopgm 5 17 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pbmtopgm 5 0 testgrid.pbm"
+invCmd "pbmtopgm 0 9 testgrid.pbm"
+invCmd "pbmtopgm 15 5 testgrid.pbm"
+invCmd "pbmtopgm 5 17 testgrid.pbm"
diff --git a/test/pgmhist.test b/test/pgmhist.test
index a47ab71e..5c458a57 100755
--- a/test/pgmhist.test
+++ b/test/pgmhist.test
@@ -26,30 +26,9 @@ pgmramp -lr 256 1 | pgmhist -machine -decile   | \
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pgmhist -median   -quartile testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmhist -median   -decile   testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmhist -quartile -decile   testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmhist testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pgmhist -median   -quartile testgrid.pbm"
+invCmd "pgmhist -median   -decile   testgrid.pbm"
+invCmd "pgmhist -quartile -decile   testgrid.pbm"
+invCmd "pgmhist testimg.ppm"
diff --git a/test/pgmmake.ok b/test/pgmmake.ok
index ac9b968c..9460162d 100644
--- a/test/pgmmake.ok
+++ b/test/pgmmake.ok
@@ -1,4 +1,16 @@
 Test 1
+P2
+1 1
+255
+0
+P2
+1 1
+255
+255
+P2
+1 1
+2
+1
 3662611538 2513
 3109612402 5012
 Test Invalid
@@ -10,3 +22,4 @@ Expected failure 5 (no output)
 Expected failure 6 (no output)
 Expected failure 7 (no output)
 Expected failure 8 (no output)
+Expected failure 9 (no output)
diff --git a/test/pgmmake.test b/test/pgmmake.test
index 80997d07..d8e248d4 100755
--- a/test/pgmmake.test
+++ b/test/pgmmake.test
@@ -4,56 +4,22 @@
 
 echo "Test 1"
 
+pgmmake -plain 0 1 1
+pgmmake -plain 1 1 1
+pgmmake -plain -maxval=2 0.5 1 1
 pgmmake 1 50 50 | cksum
 pgmmake .2 50 100 -maxval=5 | cksum
 
-
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-pgmmake 100  5 5 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake 1.01 5 5 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake .5   5   > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake .5       > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake -maxval=5        5 5 > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake -maxval=0     .5 5 5 > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake -maxval=-1    .5 5 5 > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmmake -maxval=65536 .5 5 5 > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pgmmake"
+invCmd "pgmmake 100  5 5"
+invCmd "pgmmake 1.01 5 5"
+invCmd "pgmmake .5   5"
+invCmd "pgmmake .5"
+invCmd "pgmmake -maxval=5        5 5"
+invCmd "pgmmake -maxval=0     .5 5 5"
+invCmd "pgmmake -maxval=-1    .5 5 5"
+invCmd "pgmmake -maxval=65536 .5 5 5"
diff --git a/test/pgmnoise-parameters.ok b/test/pgmnoise-parameters.ok
index 10a05cfa..1e321f00 100644
--- a/test/pgmnoise-parameters.ok
+++ b/test/pgmnoise-parameters.ok
@@ -1,5 +1,7 @@
+Test Invalid
 Expected failure 1 (no output)
 Expected failure 2 (no output)
 Expected failure 3 (no output)
 Expected failure 4 (no output)
 Expected failure 5 (no output)
+Expected failure 6 (no output)
diff --git a/test/pgmnoise-parameters.test b/test/pgmnoise-parameters.test
index 79c068d8..871aacf9 100755
--- a/test/pgmnoise-parameters.test
+++ b/test/pgmnoise-parameters.test
@@ -2,35 +2,13 @@
 # This script tests: pgmnoise
 # Also requires:
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
+echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-pgmnoise -maxval=255  -randomseed=1 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmnoise 100 -randomseed=1 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmnoise 100 0 -randomseed=1 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmnoise 0 100 -randomseed=1 > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pgmnoise 100 100 100 -randomseed=1 > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pgmnoise"
+invCmd "pgmnoise -maxval=255  -randomseed=1"
+invCmd "pgmnoise 100 -randomseed=1"
+invCmd "pgmnoise 100 0 -randomseed=1"
+invCmd "pgmnoise 0 100 -randomseed=1"
+invCmd "pgmnoise 100 100 100 -randomseed=1"
diff --git a/test/pgmramp.ok b/test/pgmramp.ok
index 69e3a6e5..71f92b13 100644
--- a/test/pgmramp.ok
+++ b/test/pgmramp.ok
@@ -42,8 +42,10 @@ Test 2
 Test 3
 886972785 131087
 Test Invalid
-Expected failure: -lr -tb (no output)
-Expected failure: -lr -rectangle (no output)
-Expected failure: -rectangle -ellipse (no output)
-Expected failure: insufficient parameters (no output)
-Expected failure: excessive parameters (no output)
+Expected failure 1 (no output)
+Expected failure 2 (no output)
+Expected failure 3 (no output)
+Expected failure 4 (no output)
+Expected failure 5 (no output)
+Expected failure 6 (no output)
+Expected failure 7 (no output)
diff --git a/test/pgmramp.test b/test/pgmramp.test
index d2e34885..84fe02ca 100755
--- a/test/pgmramp.test
+++ b/test/pgmramp.test
@@ -21,27 +21,16 @@ pgmramp -diagonal -maxval=510 256 256 | cksum
 
 echo "Test Invalid"
 
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
 
 for combination in "-lr -tb" "-lr -rectangle" "-rectangle -ellipse"
-do pgmramp $combination 10 10 > ${test_out} || \
-  printf "Expected failure: $combination "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-done
+  do
+    invCmd "pgmramp ${combination} 10 10"
+  done
 
-pgmramp -lr     1 > ${test_out} || \
-  printf "Expected failure: insufficient parameters "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pgmramp -lr 10 0"
+invCmd "pgmramp -lr 0 10"
+invCmd "pgmramp -lr 1"
+invCmd "pgmramp -tb 1 1 1"
 
-pgmramp -tb 1 1 1 > ${test_out} || \
-  printf "Expected failure: excessive parameters "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
diff --git a/test/pnmcat.test b/test/pnmcat.test
index 02fefd38..8779638b 100755
--- a/test/pnmcat.test
+++ b/test/pnmcat.test
@@ -59,7 +59,7 @@ cat ${diag_pgm} | pnmcat -tb -plain | sed 's/ *$//'
 
 rm ${diag_pgm}
 
-pgmramp -diag 8 8 -maxval 7 | ppmtoppm > ${diag_ppm} 
+pgmramp -diag 8 8 -maxval 7 | ppmtoppm > ${diag_ppm}
 
 echo "Test 7.  Should print 2097565808 394 twice"
 pnmcat -lr -black ${diag_ppm} ${diag_ppm} | tee ${diag2lr_ppm} | cksum
@@ -70,7 +70,7 @@ pnmcat -tb ${diag_ppm} ${diag_ppm} | tee ${diag2tb_ppm} | cksum
 
 echo "Test 9.  Should print 4288335051 586 three times"
 pnmcat -lr ${diag_ppm} ${diag_ppm} ${diag_ppm} | cksum
-pnmcat -lr ${diag_ppm}  ${diag2lr_ppm} | cksum 
+pnmcat -lr ${diag_ppm}  ${diag2lr_ppm} | cksum
 cat ${diag2lr_ppm} | pnmcat -lr - ${diag_ppm} | cksum
 
 echo "Test 10.  Should print 642720605 586 three times"
@@ -100,82 +100,30 @@ rm ${diag_ppm}
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
 # direction not specified
-pnmcat testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcat testgrid.pbm testimg.ppm"
 
 # both directions specified
-pnmcat -topbottom -leftright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcat -topbottom -leftright testgrid.pbm testimg.ppm"
 
 # both pad colors specified
-pnmcat -topbottom -white -black testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcat -topbottom -white -black testgrid.pbm testimg.ppm"
 
 # justification parameters overspecified
-pnmcat -lr -jtop -jbottom testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -lr -jtop -jcenter testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -lr -jcenter -jbottom testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -tb -jleft -jright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -tb -jleft -jcenter testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -tb -jcenter -jright testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcat -lr -jtop -jbottom testgrid.pbm testimg.ppm"
+invCmd "pnmcat -lr -jtop -jcenter testgrid.pbm testimg.ppm"
+invCmd "pnmcat -lr -jcenter -jbottom testgrid.pbm testimg.ppm"
+invCmd "pnmcat -tb -jleft -jright testgrid.pbm testimg.ppm"
+invCmd "pnmcat -tb -jleft -jcenter testgrid.pbm testimg.ppm"
+invCmd "pnmcat -tb -jcenter -jright testgrid.pbm testimg.ppm"
 
 # justification parameter in the wrong direction
-pnmcat -lr -jleft    testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -lr -jright   testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -tb -jtop     testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcat -tb -jbottom  testgrid.pbm testimg.ppm > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcat -lr -jleft    testgrid.pbm testimg.ppm"
+invCmd "pnmcat -lr -jright   testgrid.pbm testimg.ppm"
+invCmd "pnmcat -tb -jtop     testgrid.pbm testimg.ppm"
+invCmd "pnmcat -tb -jbottom  testgrid.pbm testimg.ppm"
 
 # more than one input image from standard input
 cat testgrid.pbm | pnmcat -lr - - testimg.ppm > ${test_out} || \
diff --git a/test/pnmcolormap.test b/test/pnmcolormap.test
index b34a0360..953dece3 100755
--- a/test/pnmcolormap.test
+++ b/test/pnmcolormap.test
@@ -32,49 +32,16 @@ pnmcolormap -center 64 testimg.ppm | cmp -s ${map} - && echo ok || echo bad
 pnmcolormap -spreadbrightness 64 testimg.ppm | cmp -s ${map} - && echo ok || echo bad
 pnmcolormap -splitpixelct 64 testimg.ppm | cmp -s ${map} - && echo ok || echo bad
 rm ${map}
+
 echo
 echo "Test Invalid."
 
-echo 1>&2
-echo "Invalid command-line arguments." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-pnmcolormap 0 testimg.ppm   > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcolormap -1 testimg.ppm  > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcolormap 0.1 testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcolormap -center -meancolor 16 testimg.ppm    > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcolormap -center -meanpixel 16 testimg.ppm    > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmcolormap -meancolor -meanpixel 16 testimg.ppm > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
 
-pnmcolormap -spreadbrightness -spreadluminosity 16 \
-  testimg.ppm > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "pnmcolormap 0 testimg.ppm  "
+invCmd "pnmcolormap -1 testimg.ppm "
+invCmd "pnmcolormap 0.1 testimg.ppm"
+invCmd "pnmcolormap -center -meancolor 16 testimg.ppm   "
+invCmd "pnmcolormap -center -meanpixel 16 testimg.ppm   "
+invCmd "pnmcolormap -meancolor -meanpixel 16 testimg.ppm"
+invCmd "pnmcolormap -spreadbrightness -spreadluminosity 16 testimg.ppm"
diff --git a/test/pnmindex.test b/test/pnmindex.test
index 51e61532..5b427da2 100755
--- a/test/pnmindex.test
+++ b/test/pnmindex.test
@@ -1,7 +1,7 @@
 #! /bin/sh
 # This script tests: pnmindex
 # Also requires: pamcat pamscale pbmtext pnmcolormap pnmindex
-# Also requires: pnminvert pnmquant pnmremap 
+# Also requires: pnminvert pnmquant pnmremap
 
 echo "Test 1. Should print 3391481002 889"
 pnmindex maze.pbm | cksum
@@ -31,30 +31,17 @@ pnmindex -size 50 -across=2 -noquant testimg.ppm testimg.ppm testimg.ppm \
 
 echo "Test Invalid"
 
-test_out=${tmpdir}/test_out
-n=1
-
-# define function
-invalidCmd () { $1 > ${test_out} && printf "Unexpected success $n " || \
-  printf "Expected failure $n "
-  test -s ${test_out} && echo "(unexpected output)" || echo "(no output)"
-  rm -f ${test_out}
-  n=$(($n + 1)); }
-
-echo 1>&2
-echo "Invalid command-line arguments." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-invalidCmd "pnmindex -size -1 testgrid.pbm"
-invalidCmd "pnmindex -size  0 testgrid.pbm"
-invalidCmd "pnmindex -size    testgrid.pbm"
-invalidCmd "pnmindex -across -1 testgrid.pbm"
-invalidCmd "pnmindex -across  0 testgrid.pbm"
-invalidCmd "pnmindex -across    testgrid.pbm"
-invalidCmd "pnmindex -colors -1 testgrid.pbm"
-invalidCmd "pnmindex -colors  0 testgrid.pbm"
-invalidCmd "pnmindex -colors    testgrid.pbm"
-invalidCmd "pnmindex -quant -noquant testgrid.pbm"
-invalidCmd "pnmindex -colors 100 -noquant testgrid.pbm"
-invalidCmd "pnmindex"
+. ${srcdir}/test-invalid.inc
+
+invCmd "pnmindex -size -1 testgrid.pbm"
+invCmd "pnmindex -size  0 testgrid.pbm"
+invCmd "pnmindex -size    testgrid.pbm"
+invCmd "pnmindex -across -1 testgrid.pbm"
+invCmd "pnmindex -across  0 testgrid.pbm"
+invCmd "pnmindex -across    testgrid.pbm"
+invCmd "pnmindex -colors -1 testgrid.pbm"
+invCmd "pnmindex -colors  0 testgrid.pbm"
+invCmd "pnmindex -colors    testgrid.pbm"
+invCmd "pnmindex -quant -noquant testgrid.pbm"
+invCmd "pnmindex -colors 100 -noquant testgrid.pbm"
+invCmd "pnmindex"
diff --git a/test/pnmpsnr.test b/test/pnmpsnr.test
index efabe9aa..6ea05aed 100755
--- a/test/pnmpsnr.test
+++ b/test/pnmpsnr.test
@@ -27,32 +27,11 @@ pnmpsnr  testimg.ppm  testimg.ppm -target1=1000 -target2=1000 -target3=1000
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pnmpsnr ${b_pbm} ${w_pbm} ${b_pbm}     > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmpsnr ${b_pbm}                       > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmpsnr ${b_pbm} ${w_pbm} -target1=100 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmpsnr                   -machine     > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pnmpsnr ${b_pbm} ${w_pbm} ${b_pbm}    "
+invCmd "pnmpsnr ${b_pbm}                      "
+invCmd "pnmpsnr ${b_pbm} ${w_pbm} -target1=100"
+invCmd "pnmpsnr                   -machine    "
 
 rm ${b_pbm} ${w_pbm}
diff --git a/test/pnmtile.test b/test/pnmtile.test
index 74bae013..35addbec 100755
--- a/test/pnmtile.test
+++ b/test/pnmtile.test
@@ -21,29 +21,9 @@ echo ${PIPESTATUS[@]} ":" $?
 
 rm ${testimg2_ppm} ${testimg4_ppm}
 
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-pnmtile 100 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmtile 100 0 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmtile 0 100 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-pnmtile 100 100 100 testgrid.pbm > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "pnmtile 100 testgrid.pbm"
+invCmd "pnmtile 100 0 testgrid.pbm"
+invCmd "pnmtile 0 100 testgrid.pbm"
+invCmd "pnmtile 100 100 100 testgrid.pbm"
diff --git a/test/ppmbrighten.ok b/test/ppmbrighten.ok
index 3895dbd0..95c90d24 100644
--- a/test/ppmbrighten.ok
+++ b/test/ppmbrighten.ok
@@ -4,8 +4,6 @@ Test 2: Should print 295150171 101484
 295150171 101484
 Test 3: Should print 1
 1
-Test Error: Should print 1 four times
-1
-1
-1
-1
+Test Invalid
+Expected failure 1 (no output)
+Expected failure 2 (no output)
diff --git a/test/ppmbrighten.test b/test/ppmbrighten.test
index e346d1d0..8ae1d744 100755
--- a/test/ppmbrighten.test
+++ b/test/ppmbrighten.test
@@ -1,6 +1,6 @@
 #! /bin/sh
 # This script tests: ppmbrighten
-# Also requires: pnmnorm pambrighten pamsumm 
+# Also requires: pnmnorm pambrighten pamsumm
 
 # Failure message
 ## Ppmbrighten is sensitive to subtle differences in floating point math.
@@ -20,22 +20,11 @@ echo "Test 3: Should print 1"
 ppmbrighten -v 100 -normalize testimg.ppm | pamsumm --mean | \
  awk '{print ($NF > 132.0) && ($NF < 132.2)}'
 
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
 
-echo "Test Error: Should print 1 four times"
+echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-output_ppm=${tmpdir}/output.ppm
+. ${srcdir}/test-invalid.inc
 
-pambrighten -v -120 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
-pambrighten -s -120 testimg.ppm > ${output_ppm}
-echo $?
-test -s ${output_ppm}
-echo $?
+invCmd "pambrighten -v -120 testimg.ppm"
+invCmd "pambrighten -s -120 testimg.ppm"
 
-rm ${output_ppm}
diff --git a/test/ppmforge-parameters.test b/test/ppmforge-parameters.test
index ba436bf0..0525e7af 100755
--- a/test/ppmforge-parameters.test
+++ b/test/ppmforge-parameters.test
@@ -5,61 +5,31 @@
 echo "Test 1: Should print 256 256"
 
 # Default size is 256 256
-ppmforge -night | pamfile -size
+ppmforge -night -seed=1 | pamfile -size
 
 echo "Test 2: Should print 40 30"
 
 # Width is adjusted if not even
 # becomes 40 in this case
-ppmforge -night -width=39 -height=30 | pamfile -size
+ppmforge -night -seed=1 -width=39 -height=30 | pamfile -size
 
 echo "Test 3: Should print 90 90"
 
 # Width is adjusted if smaller than height
 # brought up to 90 in this case
-ppmforge -night -width=80 -height=90 | pamfile -size
+ppmforge -night -seed=1 -width=80 -height=90 | pamfile -size
 
 echo "Test Invalid"
 
 tmpdir=${tmpdir:-/tmp}
 test_out=${tmpdir}/test_out
 
-echo 1>&2
-echo "Invalid command-line arguments." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
+. ${srcdir}/test-invalid.inc
 
-ppmforge -night  -dimension=0  > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge  -dimension=10  > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge  -dimension=-1  > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge -clouds -mesh=1.99    > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge -clouds -power=0      > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge         -ice=-1       > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmforge         -glaciers=-1  > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "ppmforge -seed=0 -night -dimension=0"
+invCmd "ppmforge -seed=0 -dimension=10"
+invCmd "ppmforge -seed=0 -dimension=-1"
+invCmd "ppmforge -seed=0 -clouds -mesh=1.99"
+invCmd "ppmforge -seed=0 -clouds -power=0"
+invCmd "ppmforge -seed=0 -ice=-1"
+invCmd "ppmforge -seed=0 -glaciers=-1"
diff --git a/test/ppmhist.test b/test/ppmhist.test
index 27ae9cea..1e814eb7 100755
--- a/test/ppmhist.test
+++ b/test/ppmhist.test
@@ -27,25 +27,8 @@ ppmpat -madras --color=rgb:00/00/00,rgb:31/58/a3,rgb:ff/ff/ff 25 25 | \
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-ppmhist -hexcolor -float testimg.ppm > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmhist -hexcolor -map   testimg.ppm > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmhist -float    -map   testimg.ppm > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "ppmhist -hexcolor -float testimg.ppm"
+invCmd "ppmhist -hexcolor -map   testimg.ppm"
+invCmd "ppmhist -float    -map   testimg.ppm"
diff --git a/test/ppmmake.ok b/test/ppmmake.ok
index 0231874f..e365bd9e 100644
--- a/test/ppmmake.ok
+++ b/test/ppmmake.ok
@@ -1,6 +1,14 @@
 Test 1
+P3
+1 1
+5
+0 0 0
+P3
+1 1
+65535
+65535 65535 65535
 2477651508 15012
-4294967295 0
+135932096 23
 2378991101 7513
 Test Invalid
 Expected failure 1 (no output)
diff --git a/test/ppmmake.test b/test/ppmmake.test
index fb7bf74a..295e0bf4 100755
--- a/test/ppmmake.test
+++ b/test/ppmmake.test
@@ -4,66 +4,24 @@
 
 echo "Test 1"
 
-ppmmake rgb:ff/80/80 50 100 -maxval=5 | cksum
-ppmmake rgbi:0.5/1.0/0 2   | cksum
+ppmmake -maxval=5 -plain rgb:00/00/00 1 1
+ppmmake -maxval=65535 -plain rgb:ff/ff/ff 1 1
+ppmmake -maxval=5 rgb:ff/80/80 50 100 | cksum
+ppmmake rgbi:0.5/1.0/0 2 2 | cksum
 ppmmake red 50 50  | cksum
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-ppmmake rgb:gg/00/00  2 2  > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake rgb:ff/ff/00  2    > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake rgbi:1.1/0/0  2 2  > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake rgbi:1.0/.5   2 2  > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake rainbow       2 2  > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake               2 2  > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake blue -maxval=0 2 2  > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake blue -maxval=-1 2 2  > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmmake blue -maxval=65536 2 2  > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-RGBDEF=/dev/null ppmmake red 2 2 > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "ppmmake rgb:gg/00/00  2 2"
+invCmd "ppmmake rgb:ff/ff/00  2"
+invCmd "ppmmake rgbi:1.1/0/0  2 2"
+invCmd "ppmmake rgbi:1.0/.5   2 2"
+invCmd "ppmmake rainbow       2 2"
+invCmd "ppmmake               2 2"
+invCmd "ppmmake blue -maxval=0 2 2"
+invCmd "ppmmake blue -maxval=-1 2 2"
+invCmd "ppmmake blue -maxval=65536 2 2"
+export  RGBDEF=/dev/null
+invCmd "ppmmake red 2 2"
diff --git a/test/ppmpat.test b/test/ppmpat.test
index 48c2460f..00f8421e 100755
--- a/test/ppmpat.test
+++ b/test/ppmpat.test
@@ -41,58 +41,17 @@ ppmpat -argyle2 --color=rgb:00/00/00,rgb:ff/80/80,rgb:e0/e0/e0 12 18 | cksum
 
 echo "Test Invalid"
 
-tmpdir=${tmpdir:-/tmp}
-test_out=${tmpdir}/test_out
-
-echo 1>&2
-echo "Invalid command-line argument combinations." 1>&2
-echo "Error messages should appear below the line." 1>&2
-echo "-----------------------------------------------------------" 1>&2
-
-ppmpat -g2 -g3 10 10 > ${test_out} || \
-  printf "Expected failure 1 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -madras -tartan 10 10 > ${test_out} || \
-  printf "Expected failure 2 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -poles -squig 10 10 > ${test_out} || \
-  printf "Expected failure 3 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -camo -anticamo 10 10 > ${test_out} || \
-  printf "Expected failure 4 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -argyle1 -argyle2 10 10 > ${test_out} || \
-  printf "Expected failure 5 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat 10 10 > ${test_out} || \
-  printf "Expected failure 6 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -g2 10 > ${test_out} || \
-  printf "Expected failure 7 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -g2 10 10 10 > ${test_out} || \
-  printf "Expected failure 8 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -g2 10 > ${test_out} || \
-  printf "Expected failure 9 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+. ${srcdir}/test-invalid.inc
+
+invCmd "ppmpat -g2 -g3 10 10"
+invCmd "ppmpat -madras -tartan 10 10"
+invCmd "ppmpat -poles -squig 10 10"
+invCmd "ppmpat -camo -anticamo 10 10"
+invCmd "ppmpat -argyle1 -argyle2 10 10"
+invCmd "ppmpat 10 10"
+invCmd "ppmpat -g2 10"
+invCmd "ppmpat -g2 10 10 10"
+invCmd "ppmpat -g2 10"
 
 clist1="-color=rgb:00/00/00"
 clist2="-color=rgb:00/00/00,rgb:00/00/ff"
@@ -100,90 +59,24 @@ clist3="-color=rgb:00/00/00,rgb:00/00/ff,rgb:00/ff/ff"
 clist4="-color=rgb:00/00/00,rgb:00/00/ff,rgb:00/ff/ff,rgb:ff/ff/ff"
 
 # These patterns require exactly 2 colors
-ppmpat -gingham2 ${clist1} 10 10 > ${test_out} || \
-  printf "Expected failure 10 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -argyle1  ${clist1} 10 10 > ${test_out} || \
-  printf "Expected failure 11 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -gingham2 ${clist3} 10 10 > ${test_out} || \
-  printf "Expected failure 12 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -argyle1  ${clist3} 10 10 > ${test_out} || \
-  printf "Expected failure 13 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "ppmpat -gingham2 ${clist1} 10 10"
+invCmd "ppmpat -argyle1  ${clist1} 10 10"
+invCmd "ppmpat -gingham2 ${clist3} 10 10"
+invCmd "ppmpat -argyle1  ${clist3} 10 10"
 
 # These require exactly 3 colors
-ppmpat -gingham3 ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 14 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -argyle2  ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 15 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -madras   ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 16 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -tartan   ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 17 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -gingham3 ${clist4} 10 10 > ${test_out} || \
-  printf "Expected failure 18 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -argyle2  ${clist4} 10 10 > ${test_out} || \
-  printf "Expected failure 19 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -madras   ${clist4} 10 10 > ${test_out} || \
-  printf "Expected failure 20 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -tartan   ${clist4} 10 10 > ${test_out} || \
-  printf "Expected failure 21 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-# These require at least 3 colors
-ppmpat -squig    ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 22 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -camo     ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 23 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -anticamo ${clist2} 10 10 > ${test_out} || \
-  printf "Expected failure 24 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "ppmpat -gingham3 ${clist2} 10 10"
+invCmd "ppmpat -argyle2  ${clist2} 10 10"
+invCmd "ppmpat -madras   ${clist2} 10 10"
+invCmd "ppmpat -tartan   ${clist2} 10 10"
+invCmd "ppmpat -gingham3 ${clist4} 10 10"
+invCmd "ppmpat -argyle2  ${clist4} 10 10"
+invCmd "ppmpat -madras   ${clist4} 10 10"
+invCmd "ppmpat -tartan   ${clist4} 10 10"
+invCmd "ppmpat -squig    ${clist2} 10 10"
+invCmd "ppmpat -camo     ${clist2} 10 10"
+invCmd "ppmpat -anticamo ${clist2} 10 10"
 
 # The squig pattern has an aspect ratio restriction
-ppmpat -squig ${clist3} 10 250  > ${test_out} || \
-  printf "Expected failure 25 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
-
-ppmpat -squig ${clist3} 500 20  > ${test_out} || \
-  printf "Expected failure 26 "
-  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
-  rm -f ${test_out}
+invCmd "ppmpat -squig ${clist3} 10 250"
+invCmd "ppmpat -squig ${clist3} 500 20"
diff --git a/test/test-invalid.inc b/test/test-invalid.inc
new file mode 100644
index 00000000..e24cfd3f
--- /dev/null
+++ b/test/test-invalid.inc
@@ -0,0 +1,16 @@
+echo 1>&2
+echo "Invalid command-line argument combination(s)." 1>&2
+echo "Error message(s) should appear below the line." 1>&2
+echo "-----------------------------------------------------------" 1>&2
+
+tmpdir=${tmpdir:-/tmp}
+test_out=${tmpdir}/test_out
+
+# define function
+invCmd () { $1 > ${test_out} && \
+  printf "Unexpected success ${testcnt} " || printf "Expected failure ${testcnt} "
+  test -s ${test_out} && echo "unexpected output" || echo "(no output)"
+  rm -f ${test_out}
+  testcnt=$(($testcnt +1)); }
+
+testcnt=1