grep: add --max-count command line option

This patch adds a command line option analogous to that of GNU
grep(1)'s -m / --max-count, which users might already be used to.
This makes it possible to limit the amount of matches shown in the
output while keeping the functionality of other options such as -C
(show code context) or -p (show containing function), which would be
difficult to do with a shell pipeline (e.g. head(1)).

Signed-off-by: Carlos López 00xc@protonmail.com
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Carlos López 2022-06-22 19:47:32 +00:00 committed by Junio C Hamano
parent f770e9f396
commit 68437ede53
5 changed files with 108 additions and 1 deletions

View File

@ -23,6 +23,7 @@ SYNOPSIS
[--break] [--heading] [-p | --show-function]
[-A <post-context>] [-B <pre-context>] [-C <context>]
[-W | --function-context]
[(-m | --max-count) <num>]
[--threads <num>]
[-f <file>] [-e] <pattern>
[--and|--or|--not|(|)|-e <pattern>...]
@ -238,6 +239,14 @@ providing this option will cause it to die.
`git diff` works out patch hunk headers (see 'Defining a
custom hunk-header' in linkgit:gitattributes[5]).
-m <num>::
--max-count <num>::
Limit the amount of matches per file. When using the `-v` or
`--invert-match` option, the search stops after the specified
number of non-matches. A value of -1 will return unlimited
results (the default). A value of 0 will exit immediately with
a non-zero status.
--threads <num>::
Number of grep worker threads to use.
See `grep.threads` in 'CONFIGURATION' for more information.

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@ -961,6 +961,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
N_("allow calling of grep(1) (ignored by this build)"),
PARSE_OPT_NOCOMPLETE),
OPT_INTEGER('m', "max-count", &opt.max_count,
N_("maximum number of results per file")),
OPT_END()
};
grep_prefix = prefix;
@ -1101,6 +1103,13 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
if (recurse_submodules && untracked)
die(_("--untracked not supported with --recurse-submodules"));
/*
* Optimize out the case where the amount of matches is limited to zero.
* We do this to keep results consistent with GNU grep(1).
*/
if (opt.max_count == 0)
return 1;
if (show_in_pager) {
if (num_threads > 1)
warning(_("invalid option combination, ignoring --threads"));

2
grep.c
View File

@ -1615,7 +1615,7 @@ static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int colle
return 0;
goto next_line;
}
if (hit) {
if (hit && (opt->max_count < 0 || count < opt->max_count)) {
count++;
if (opt->status_only)
return 1;

2
grep.h
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@ -171,6 +171,7 @@ struct grep_opt {
int show_hunk_mark;
int file_break;
int heading;
int max_count;
void *priv;
void (*output)(struct grep_opt *opt, const void *data, size_t size);
@ -181,6 +182,7 @@ struct grep_opt {
.relative = 1, \
.pathname = 1, \
.max_depth = -1, \
.max_count = -1, \
.pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED, \
.colors = { \
[GREP_COLOR_CONTEXT] = "", \

View File

@ -77,6 +77,7 @@ test_expect_success setup '
# Say hello.
function hello() {
echo "Hello world."
echo "Hello again."
} # hello
# Still a no-op.
@ -595,6 +596,92 @@ test_expect_success 'grep --files-without-match --quiet' '
test_must_be_empty actual
'
test_expect_success 'grep --max-count 0 (must exit with non-zero)' '
test_must_fail git grep --max-count 0 foo >actual &&
test_must_be_empty actual
'
test_expect_success 'grep --max-count 3' '
cat >expected <<-EOF &&
file:foo mmap bar
file:foo_mmap bar
file:foo_mmap bar mmap
EOF
git grep --max-count 3 foo >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count -1 (no limit)' '
cat >expected <<-EOF &&
file:foo mmap bar
file:foo_mmap bar
file:foo_mmap bar mmap
file:foo mmap bar_mmap
file:foo_mmap bar mmap baz
EOF
git grep --max-count -1 foo >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 1 --context 2' '
cat >expected <<-EOF &&
file-foo mmap bar
file:foo_mmap bar
file-foo_mmap bar mmap
EOF
git grep --max-count 1 --context 1 foo_mmap >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 1 --show-function' '
cat >expected <<-EOF &&
hello.ps1=function hello() {
hello.ps1: echo "Hello world."
EOF
git grep --max-count 1 --show-function Hello hello.ps1 >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 2 --show-function' '
cat >expected <<-EOF &&
hello.ps1=function hello() {
hello.ps1: echo "Hello world."
hello.ps1: echo "Hello again."
EOF
git grep --max-count 2 --show-function Hello hello.ps1 >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 1 --count' '
cat >expected <<-EOF &&
hello.ps1:1
EOF
git grep --max-count 1 --count Hello hello.ps1 >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 1 (multiple files)' '
cat >expected <<-EOF &&
hello.c:#include <stdio.h>
hello.ps1:# No-op.
EOF
git grep --max-count 1 -e o -- hello.\* >actual &&
test_cmp expected actual
'
test_expect_success 'grep --max-count 1 --context 1 (multiple files)' '
cat >expected <<-EOF &&
hello.c-#include <assert.h>
hello.c:#include <stdio.h>
hello.c-
--
hello.ps1:# No-op.
hello.ps1-function dummy() {}
EOF
git grep --max-count 1 --context 1 -e o -- hello.\* >actual &&
test_cmp expected actual
'
cat >expected <<EOF
file:foo mmap bar_mmap
EOF