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authorRob Landley <rob@landley.net>2005-05-09 21:42:42 +0000
committerRob Landley <rob@landley.net>2005-05-09 21:42:42 +0000
commit540d3f60f378ed26962501c33b335623fe5fb0fa (patch)
treed1d847dde8db22ab7af9a24fb018250bb51060fb
parentb9dfb8c03febea78ab1924b4924c381ca983891c (diff)
downloadbusybox-540d3f60f378ed26962501c33b335623fe5fb0fa.tar.gz
Patch from Shaun Jackman:
> This patch modfies expr to use portable POSIX regex rather than BSD > regex. ... > This updated patch implements an anchored regex by checking that the > match starts at offset 0. More to the point, this patch uses the same regex that sed.c is already using (opportunity to suck in less library code), and even building a dynamically linked busybox with just expr the result is a slightly smaller binary (by 94 bytes, I dunno what nm --size-sort has to say about it because I didn't build with debug info, since that changes the binary size a lot by disabling optimization...) Your mileage may vary. Handle with caution. Do not taunt happy fun ball.
-rw-r--r--coreutils/expr.c37
1 files changed, 15 insertions, 22 deletions
diff --git a/coreutils/expr.c b/coreutils/expr.c
index cbbd4cd03..3f052d92a 100644
--- a/coreutils/expr.c
+++ b/coreutils/expr.c
@@ -245,10 +245,9 @@ static int arithmetic_common (VALUE *l, VALUE *r, int op)
static VALUE *docolon (VALUE *sv, VALUE *pv)
{
VALUE *v;
- const char *errmsg;
- struct re_pattern_buffer re_buffer;
- struct re_registers re_regs;
- int len;
+ regex_t re_buffer;
+ const int NMATCH = 2;
+ regmatch_t re_regs[NMATCH];
tostring (sv);
tostring (pv);
@@ -260,27 +259,22 @@ of a basic regular expression is not portable; it is being ignored",
pv->u.s);
}
- len = strlen (pv->u.s);
memset (&re_buffer, 0, sizeof (re_buffer));
- memset (&re_regs, 0, sizeof (re_regs));
- re_buffer.allocated = 2 * len;
- re_buffer.buffer = (unsigned char *) xmalloc (re_buffer.allocated);
- re_buffer.translate = 0;
- re_syntax_options = RE_SYNTAX_POSIX_BASIC;
- errmsg = re_compile_pattern (pv->u.s, len, &re_buffer);
- if (errmsg) {
- bb_error_msg_and_die("%s", errmsg);
- }
-
- len = re_match (&re_buffer, sv->u.s, strlen (sv->u.s), 0, &re_regs);
- if (len >= 0) {
+ memset (re_regs, 0, sizeof (*re_regs));
+ if( regcomp (&re_buffer, pv->u.s, 0) != 0 )
+ bb_error_msg_and_die("Invalid regular expression");
+
+ /* expr uses an anchored pattern match, so check that there was a
+ * match and that the match starts at offset 0. */
+ if (regexec (&re_buffer, sv->u.s, NMATCH, re_regs, 0) != REG_NOMATCH &&
+ re_regs[0].rm_so == 0) {
/* Were \(...\) used? */
- if (re_buffer.re_nsub > 0) { /* was (re_regs.start[1] >= 0) */
- sv->u.s[re_regs.end[1]] = '\0';
- v = str_value (sv->u.s + re_regs.start[1]);
+ if (re_buffer.re_nsub > 0) {
+ sv->u.s[re_regs[1].rm_eo] = '\0';
+ v = str_value (sv->u.s + re_regs[1].rm_so);
}
else
- v = int_value (len);
+ v = int_value (re_regs[0].rm_eo);
}
else {
/* Match failed -- return the right kind of null. */
@@ -289,7 +283,6 @@ of a basic regular expression is not portable; it is being ignored",
else
v = int_value (0);
}
- free (re_buffer.buffer);
return v;
}