Teach GNU grep(1)'s '-o' ('--only-matching') to 'git-grep'. This option
prints only the matching components of each line. It writes multiple
lines if more than one match exists on a given line.
For example:
$ git grep -on --column --heading git -- README.md | head -3
README.md
15:56:git
18:20:git
By using show_line_header(), 'git grep --only-matching' correctly
respects the '--header' option:
$ git grep -on --column --heading git -- README.md | head -4
README.md
15:56:git
18:20:git
19:16:git
Signed-off-by: Taylor Blau <m...@ttaylorr.com>
---
Documentation/git-grep.txt | 6 +++++-
builtin/grep.c | 1 +
grep.c | 23 ++++++++++++++++++++---
grep.h | 1 +
t/t7810-grep.sh | 33 +++++++++++++++++++++++++++++++++
5 files changed, 60 insertions(+), 4 deletions(-)
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index d451cd8883..9754923041 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -20,7 +20,7 @@ SYNOPSIS
[-c | --count] [--all-match] [-q | --quiet]
[--max-depth <depth>]
[--color[=<when>] | --no-color]
- [--break] [--heading] [-p | --show-function]
+ [--break] [--heading] [-o | --only-matching] [-p | --show-function]
[-A <post-context>] [-B <pre-context>] [-C <context>]
[-W | --function-context]
[--threads <num>]
@@ -221,6 +221,10 @@ providing this option will cause it to die.
Show the filename above the matches in that file instead of
at the start of each shown line.
+--o::
+--only-matching::
+ Show only the matching part of the lines.
+
-p::
--show-function::
Show the preceding line that contains the function name of
diff --git a/builtin/grep.c b/builtin/grep.c
index 5c83f17759..5028bf96cf 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -851,6 +851,7 @@ int cmd_grep(int argc, const char **argv, const char
*prefix)
N_("print empty line between matches from different
files")),
OPT_BOOL(0, "heading", &opt.heading,
N_("show filename only once above matches from same
file")),
+ OPT_BOOL('o', "only-matching", &opt.only_matching, N_("show
only matches")),
OPT_GROUP(""),
OPT_CALLBACK('C', "context", &opt, N_("n"),
N_("show <n> context lines before and after matches"),
diff --git a/grep.c b/grep.c
index 89dd719e4d..da3f8e6266 100644
--- a/grep.c
+++ b/grep.c
@@ -1422,11 +1422,13 @@ static void show_line(struct grep_opt *opt, char *bol,
char *eol,
}
}
show_line_header(opt, name, lno, cno, sign);
- if (opt->color) {
+ if (opt->color || opt->only_matching) {
regmatch_t match;
enum grep_context ctx = GREP_CONTEXT_BODY;
int ch = *eol;
int eflags = 0;
+ int first = 1;
+ int offset = 1;
if (sign == ':')
match_color = opt->color_match_selected;
@@ -1443,16 +1445,31 @@ static void show_line(struct grep_opt *opt, char *bol,
char *eol,
if (match.rm_so == match.rm_eo)
break;
- output_color(opt, bol, match.rm_so, line_color);
+ if (!opt->only_matching)
+ output_color(opt, bol, match.rm_so, line_color);
+ else if (!first) {
+ /*
+ * We are given --only-matching, and this is not
+ * the first match on a line. Reprint the
+ * newline and header before showing another
+ * match.
+ */
+ opt->output(opt, "\n", 1);
+ show_line_header(opt, name, lno,
+ offset+match.rm_so, sign);
+ }
output_color(opt, bol + match.rm_so,
match.rm_eo - match.rm_so, match_color);
+ offset += match.rm_eo;
bol += match.rm_eo;
rest -= match.rm_eo;
eflags = REG_NOTBOL;
+ first = 0;
}
*eol = ch;
}
- output_color(opt, bol, rest, line_color);
+ if (!opt->only_matching)
+ output_color(opt, bol, rest, line_color);
opt->output(opt, "\n", 1);
}
diff --git a/grep.h b/grep.h
index 08a0b391c5..24c1460100 100644
--- a/grep.h
+++ b/grep.h
@@ -126,6 +126,7 @@ struct grep_opt {
const char *prefix;
int prefix_length;
regex_t regexp;
+ int only_matching;
int linenum;
int columnnum;
int invert;
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index a03c3416e7..ef7f4ce725 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -1420,6 +1420,39 @@ test_expect_success 'grep --heading' '
test_cmp expected actual
'
+cat >expected <<EOF
+file:1:5:mmap
+file:2:5:mmap
+file:3:5:mmap
+file:3:14:mmap
+file:4:5:mmap
+file:4:14:mmap
+file:5:5:mmap
+file:5:14:mmap
+EOF
+
+test_expect_success 'grep --only-matching' '
+ git grep --only-matching --line-number --column mmap file >actual &&
+ test_cmp expected actual
+'
+
+cat >expected <<EOF
+file
+1:5:mmap
+2:5:mmap
+3:5:mmap
+3:14:mmap
+4:5:mmap
+4:14:mmap
+5:5:mmap
+5:14:mmap
+EOF
+
+test_expect_success 'grep --only-matching --heading' '
+ git grep --only-matching --heading --line-number --column mmap file
>actual &&
+ test_cmp expected actual
+'
+
cat >expected <<EOF
<BOLD;GREEN>hello.c<RESET>
4:int main(int argc, const <BLACK;BYELLOW>char<RESET> **argv)
--
2.17.0
