"Carlos L. via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> From: =?UTF-8?q?Carlos=20L=C3=B3pez?= <00xc@xxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxx
> ---
> ...
> Documentation/git-grep.txt | 8 ++++++++
> builtin/grep.c | 9 +++++++++
> grep.c | 2 ++
> grep.h | 2 ++
> 4 files changed, 21 insertions(+)
Tests?
> diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
> index 3d393fbac1b..19b817d5e58 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 +239,13 @@ 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).
Hmph ...
> + /*
> + * 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)
> + exit(EXIT_FAILURE);
> +
OK, so "stop before seeing any match" logically leads to "we found
nothing, so exit with non-zero".
> diff --git a/grep.c b/grep.c
> index 82eb7da1022..b32ab75cb6b 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -1686,6 +1686,8 @@ static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int colle
> bol = eol + 1;
> if (!left)
> break;
> + if (opt->max_count != -1 && count == opt->max_count)
> + break;
I would have written it "if (0 <= opt->max_count && ...)". What
happens when a trickster asks you to do "git grep -m -2"?
I guess what I am getting at is if we are better off saying that
negative means unlimited, instead of special casing -1 like this. I
didn't think it through so it may be perfectly possible that what
you wrote makes more sense than "anything negative is unlimited".
I dunno.
> left--;
> lno++;
> }
Thanks.
> 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] = "", \
>
> base-commit: 5b71c59bc3b9365075e2a175aa7b6f2b0c84ce44
