diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | Doc/Zsh/expn.yo | 12 | ||||
| -rw-r--r-- | NEWS | 3 | ||||
| -rw-r--r-- | Src/subst.c | 40 | ||||
| -rw-r--r-- | Test/D04parameter.ztst | 14 |
5 files changed, 61 insertions, 14 deletions
diff --git a/ChangeLog b/ChangeLog index 8027def03..669d31ef2 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2011-05-19 Mikael Magnusson <mikachu@gmail.com> + * 29224: Support negative LEN in ${VAR:OFFSET:LEN} like bash. + +2011-05-19 Mikael Magnusson <mikachu@gmail.com> + * 29261: Add g:: parameter expansion flag. Add note that s:: can take an empty string. @@ -14757,5 +14761,5 @@ ***************************************************** * This is used by the shell to define $ZSH_PATCHLEVEL -* $Revision: 1.5313 $ +* $Revision: 1.5314 $ ***************************************************** diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo index e39589447..ce122cade 100644 --- a/Doc/Zsh/expn.yo +++ b/Doc/Zsh/expn.yo @@ -588,7 +588,7 @@ remove the non-matched elements). xitem(tt(${)var(name)tt(:)var(offset)tt(})) item(tt(${)var(name)tt(:)var(offset)tt(:)var(length)tt(}))( This syntax gives effects similar to parameter subscripting -in the form tt($)var(name)tt({)var(start)tt(,)var(end)tt(}), but is +in the form tt($)var(name)tt([)var(start)tt(,)var(end)tt(]), but is compatible with other shells; note that both var(offset) and var(length) are interpreted differently from the components of a subscript. @@ -608,8 +608,12 @@ the option tt(KSH_ARRAYS). A negative offset counts backwards from the end of the scalar or array, so that -1 corresponds to the last character or element, and so on. -var(length) is always treated directly as a length and hence may not be -negative. The option tt(MULTIBYTE) is obeyed, i.e. the offset and length +When positive, var(length) counts from the var(offset) position +toward the end of the scalar or array. When negative, var(length) +counts back from the end. If this results in a position smaller +than var(offset), a diagnostic is printed and nothing is substituted. + +The option tt(MULTIBYTE) is obeyed, i.e. the offset and length count multibyte characters where appropriate. var(offset) and var(length) undergo the same set of shell substitutions @@ -635,7 +639,7 @@ tt(${)var(name)tt(:-)var(word)tt(}) form of substitution. Instead, a space may be inserted before the tt(-). Furthermore, neither var(offset) nor var(length) may begin with an alphabetic character or tt(&) as these are used to indicate history-style modifiers. To substitute a value from a -variable, the recommended approach is to proceed it with a tt($) as this +variable, the recommended approach is to precede it with a tt($) as this signifies the intention (parameter substitution can easily be rendered unreadable); however, as arithmetic substitution is performed, the expression tt(${var: offs}) does work, retrieving the offset from diff --git a/NEWS b/NEWS index 2d6f4ea02..d876e12aa 100644 --- a/NEWS +++ b/NEWS @@ -19,6 +19,9 @@ the command line is edited. In POSIX emulation ("emulate sh") the shell is more accurate about when it should or should not exit on errors. +The ${NAME:OFFSET:LENGTH} syntax now supports negative LENGTH, which +counts back from the end of the string. + Changes between versions 4.3.10 and 4.3.11 ------------------------------------------ diff --git a/Src/subst.c b/Src/subst.c index 822b24a40..5628c11d2 100644 --- a/Src/subst.c +++ b/Src/subst.c @@ -2839,7 +2839,8 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub) char *check_offset = check_colon_subscript(s, &check_offset2); if (check_offset) { zlong offset = mathevali(check_offset); - zlong length = (zlong)-1; + zlong length; + int length_set = 0; int offset_hack_argzero = 0; if (errflag) return NULL; @@ -2854,14 +2855,11 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub) zerr("invalid length: %s", check_offset); return NULL; } - if (check_offset) { + if (check_offset) { length = mathevali(check_offset); + length_set = 1; if (errflag) return NULL; - if (length < (zlong)0) { - zerr("invalid length: %s", check_offset); - return NULL; - } } } if (horrible_offset_hack) { @@ -2889,8 +2887,16 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub) } if (offset_hack_argzero) alen++; - if (length < 0) - length = alen; + if (length_set) { + if (length < 0) + length += alen - offset; + if (length < 0) { + zerr("substring expression: %d < %d", + length + offset, offset); + return NULL; + } + } else + length = alen; if (offset > alen) offset = alen; if (offset + length > alen) @@ -2909,6 +2915,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub) aval = newarr; } else { char *sptr, *eptr; + int given_offset; if (offset < 0) { MB_METACHARINIT(); for (sptr = val; *sptr; ) { @@ -2918,12 +2925,27 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub) if (offset < 0) offset = 0; } + given_offset = offset; MB_METACHARINIT(); + if (length_set && length < 0) + length -= offset; for (sptr = val; *sptr && offset; ) { sptr += MB_METACHARLEN(sptr); offset--; } - if (length >= 0) { + if (length_set) { + if (length < 0) { + MB_METACHARINIT(); + for (eptr = val; *eptr; ) { + eptr += MB_METACHARLEN(eptr); + length++; + } + if (length < 0) { + zerr("substring expression: %d < %d", + length + given_offset, given_offset); + return NULL; + } + } for (eptr = sptr; *eptr && length; ) { eptr += MB_METACHARLEN(eptr); length--; diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst index 84b9c1a9f..6379c8cd0 100644 --- a/Test/D04parameter.ztst +++ b/Test/D04parameter.ztst @@ -1366,6 +1366,7 @@ print ${foo:$(echo 3 + 3):`echo 4 - 3`} print ${foo: -1} print ${foo: -10} + print ${foo:5:-2} 0:Bash-style offsets, scalar >456789 >56789 @@ -1377,6 +1378,7 @@ >7 >9 >123456789 +>67 foo=(1 2 3 4 5 6 7 8 9) print ${foo:3} @@ -1389,6 +1391,7 @@ print ${foo:$(echo 3 + 3):`echo 4 - 3`} print ${foo: -1} print ${foo: -10} + print ${foo:5:-2} 0:Bash-style offsets, array >4 5 6 7 8 9 >5 6 7 8 9 @@ -1400,6 +1403,7 @@ >7 >9 >1 2 3 4 5 6 7 8 9 +>6 7 testfn() { emulate -L sh @@ -1438,3 +1442,13 @@ print ${str:0:} 1:Regression test for missing length after offset ?(eval):2: unrecognized modifier + + foo="123456789" + print ${foo:5:-6} +1:Regression test for total length < 0 in string +?(eval):2: substring expression: 3 < 5 + + foo=(1 2 3 4 5 6 7 8 9) + print ${foo:5:-6} +1:Regression test for total length < 0 in array +?(eval):2: substring expression: 3 < 5 |