From cd55f2d9332489432ba2b3093903949c6c2e3e33 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 7 Jan 2014 14:57:42 +0100 Subject: [PATCH] grep: fix two bugs with -w 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 --- findutils/grep.c | 28 +++++++++++++++++++++++++--- testsuite/grep.tests | 12 ++++++++++++ 2 files changed, 37 insertions(+), 3 deletions(-) diff --git a/findutils/grep.c b/findutils/grep.c index b8ad1bf8f..a7bc4ca9e 100644 --- a/findutils/grep.c +++ b/findutils/grep.c @@ -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 } } } diff --git a/testsuite/grep.tests b/testsuite/grep.tests index 64d99a905..412efffbb 100755 --- a/testsuite/grep.tests +++ b/testsuite/grep.tests @@ -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 -- 2.25.1