diff options
Diffstat (limited to 'misc/tst-fd_to_filename.c')
-rw-r--r-- | misc/tst-fd_to_filename.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/misc/tst-fd_to_filename.c b/misc/tst-fd_to_filename.c new file mode 100644 index 0000000000..d16c869cd3 --- /dev/null +++ b/misc/tst-fd_to_filename.c @@ -0,0 +1,101 @@ +/* Test for /proc/self/fd (or /dev/fd) pathname construction. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <fcntl.h> +#include <fd_to_filename.h> +#include <stdio.h> +#include <support/check.h> +#include <support/xunistd.h> + +/* Run a check on one value. */ +static void +check (int value) +{ + if (value < 0) + /* Negative descriptor values violate the precondition. */ + return; + + struct fd_to_filename storage; + char *actual = __fd_to_filename (value, &storage); + char expected[100]; + snprintf (expected, sizeof (expected), FD_TO_FILENAME_PREFIX "%d", value); + TEST_COMPARE_STRING (actual, expected); +} + +/* Check various ranges constructed around powers. */ +static void +check_ranges (int base) +{ + unsigned int power = 1; + do + { + for (int factor = 1; factor < base; ++factor) + for (int shift = -1000; shift <= 1000; ++shift) + check (factor * power + shift); + } + while (!__builtin_mul_overflow (power, base, &power)); +} + +/* Check that it is actually possible to use a the constructed + name. */ +static void +check_open (void) +{ + int pipes[2]; + xpipe (pipes); + + struct fd_to_filename storage; + int read_alias = xopen (__fd_to_filename (pipes[0], &storage), O_RDONLY, 0); + int write_alias = xopen (__fd_to_filename (pipes[1], &storage), O_WRONLY, 0); + + /* Ensure that all the descriptor numbers are different. */ + TEST_VERIFY (pipes[0] < pipes[1]); + TEST_VERIFY (pipes[1] < read_alias); + TEST_VERIFY (read_alias < write_alias); + + xwrite (write_alias, "1", 1); + char buf[16]; + TEST_COMPARE_BLOB ("1", 1, buf, read (pipes[0], buf, sizeof (buf))); + + xwrite (pipes[1], "2", 1); + TEST_COMPARE_BLOB ("2", 1, buf, read (read_alias, buf, sizeof (buf))); + + xwrite (write_alias, "3", 1); + TEST_COMPARE_BLOB ("3", 1, buf, read (read_alias, buf, sizeof (buf))); + + xwrite (pipes[1], "4", 1); + TEST_COMPARE_BLOB ("4", 1, buf, read (pipes[0], buf, sizeof (buf))); + + xclose (write_alias); + xclose (read_alias); + xclose (pipes[1]); + xclose (pipes[0]); +} + +static int +do_test (void) +{ + check_ranges (2); + check_ranges (10); + + check_open (); + + return 0; +} + +#include <support/test-driver.c> |