[PATCH v3 1/2] grep: add --max-count command line option
- From
- Carlos López via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Jun 22, 2022, 17:07 UTC
- Message-ID
- <5bf7244437e30ae0810e323016de892b82365b12.1655917628.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1278.v3.git.git.1655917628.gitgitgadget@gmail.com>
From: =?UTF-8?q?Carlos=20L=C3=B3pez?= <00xc@protonmail.com>
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 --- Documentation/git-grep.txt | 9 +++++++++ builtin/grep.c | 9 +++++++++ grep.c | 2 +- grep.h | 2 ++ 4 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt index 3d393fbac1b..58d944bd578 100644 --- a/Documentation/git-grep.txt +++ b/Documentation/git-grep.txt @@ -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. diff --git a/builtin/grep.c b/builtin/grep.c index bcb07ea7f75..e6bcdf860cc 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -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")); diff --git a/grep.c b/grep.c index 82eb7da1022..52a894c9890 100644 --- a/grep.c +++ b/grep.c @@ -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; diff --git a/grep.h b/grep.h index c722d25ed9d..bdcadce61b8 100644 --- a/grep.h +++ b/grep.h @@ -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] = "", \
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