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grep: fix two bugs with -w

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Unfortunately, with !EXTRA_COMPAT, "grep -w ^str" still erroneously matches "strstr".

function                                             old     new   delta
grep_file                                           1499    1510     +11

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-01-07 14:57:42 +01:00
parent 432fbd7a1a
commit cd55f2d933
2 changed files with 37 additions and 3 deletions
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28
findutils/grep.c
View File

@ -373,6 +373,9 @@ static int grep_file(FILE *file)
opt_f_not_found: ;
}
} else {
#if ENABLE_EXTRA_COMPAT
unsigned start_pos;
#endif
char *match_at;
if (!(gl->flg_mem_alocated_compiled & COMPILED)) {
@ -389,15 +392,18 @@ static int grep_file(FILE *file)
#if !ENABLE_EXTRA_COMPAT
gl->matched_range.rm_so = 0;
gl->matched_range.rm_eo = 0;
#else
start_pos = 0;
#endif
match_at = line;
opt_w_again:
//bb_error_msg("'%s' start_pos:%d line_len:%d", match_at, start_pos, line_len);
if (
#if !ENABLE_EXTRA_COMPAT
regexec(&gl->compiled_regex, match_at, 1, &gl->matched_range, 0) == 0
#else
re_search(&gl->compiled_regex, match_at, line_len,
/*start:*/ 0, /*range:*/ line_len,
start_pos, /*range:*/ line_len,
&gl->matched_range) >= 0
#endif
) {
@ -416,8 +422,24 @@ static int grep_file(FILE *file)
if (!c || (!isalnum(c) && c != '_')) {
found = 1;
} else {
match_at += gl->matched_range.rm_eo;
goto opt_w_again;
/*
* Why check gl->matched_range.rm_eo?
* Zero-length match makes -w skip the line:
* "echo foo | grep ^" prints "foo",
* "echo foo | grep -w ^" prints nothing.
* Without such check, we can loop forever.
*/
#if !ENABLE_EXTRA_COMPAT
if (gl->matched_range.rm_eo != 0) {
match_at += gl->matched_range.rm_eo;
goto opt_w_again;
}
#else
if (gl->matched_range.rm_eo > start_pos) {
start_pos = gl->matched_range.rm_eo;
goto opt_w_again;
}
#endif
}
}
}

12
testsuite/grep.tests
View File

@ -147,6 +147,18 @@ testing "grep -w doesn't stop on 1st mismatch" \
"foop foo\n" \
""
testing "grep -w ^str doesn't match str not at the beginning" \
"grep -w ^str input" \
"" \
"strstr\n" \
""
testing "grep -w ^ doesn't hang" \
"grep -w ^ input" \
"" \
"anything\n" \
""
# testing "test name" "commands" "expected result" "file input" "stdin"
# file input will be file called "input"
# test can create a file "actual" instead of writing to stdout