diff options
author | Taylor Blau <me@ttaylorr.com> | 2022-07-22 23:29:05 (GMT) |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2022-07-23 04:42:06 (GMT) |
commit | db9d67f2e9c9ea389f5558d6a168460d51631769 (patch) | |
tree | 480ef901948f38b409cc9148bca64c5f1a04d97a /builtin/cat-file.c | |
parent | 3639fefe7d1d7bf881ea6128cedc4fc503164edc (diff) | |
download | git-db9d67f2e9c9ea389f5558d6a168460d51631769.zip git-db9d67f2e9c9ea389f5558d6a168460d51631769.tar.gz git-db9d67f2e9c9ea389f5558d6a168460d51631769.tar.bz2 |
builtin/cat-file.c: support NUL-delimited input with `-z`
When callers are using `cat-file` via one of the stdin-driven `--batch`
modes, all input is newline-delimited. This presents a problem when
callers wish to ask about, e.g. tree-entries that have a newline
character present in their filename.
To support this niche scenario, introduce a new `-z` mode to the
`--batch`, `--batch-check`, and `--batch-command` suite of options that
instructs `cat-file` to treat its input as NUL-delimited, allowing the
individual commands themselves to have newlines present.
The refactoring here is slightly unfortunate, since we turn loops like:
while (strbuf_getline(&buf, stdin) != EOF)
into:
while (1) {
int ret;
if (opt->nul_terminated)
ret = strbuf_getline_nul(&input, stdin);
else
ret = strbuf_getline(&input, stdin);
if (ret == EOF)
break;
}
It's tempting to think that we could use `strbuf_getwholeline()` and
specify either `\n` or `\0` as the terminating character. But for input
on platforms that include a CR character preceeding the LF, this
wouldn't quite be the same, since `strbuf_getline(...)` will trim any
trailing CR, while `strbuf_getwholeline(&buf, stdin, '\n')` will not.
In the future, we could clean this up further by introducing a variant
of `strbuf_getwholeline()` that addresses the aforementioned gap, but
that approach felt too heavy-handed for this pair of uses.
Some tests are added in t1006 to ensure that `cat-file` produces the
same output in `--batch`, `--batch-check`, and `--batch-command` modes
with and without the new `-z` option.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin/cat-file.c')
-rw-r--r-- | builtin/cat-file.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/builtin/cat-file.c b/builtin/cat-file.c index f42782e..c3602d1 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -31,6 +31,7 @@ struct batch_options { int all_objects; int unordered; int transform_mode; /* may be 'w' or 'c' for --filters or --textconv */ + int nul_terminated; const char *format; }; @@ -614,12 +615,20 @@ static void batch_objects_command(struct batch_options *opt, struct queued_cmd *queued_cmd = NULL; size_t alloc = 0, nr = 0; - while (!strbuf_getline(&input, stdin)) { - int i; + while (1) { + int i, ret; const struct parse_cmd *cmd = NULL; const char *p = NULL, *cmd_end; struct queued_cmd call = {0}; + if (opt->nul_terminated) + ret = strbuf_getline_nul(&input, stdin); + else + ret = strbuf_getline(&input, stdin); + + if (ret) + break; + if (!input.len) die(_("empty command in input")); if (isspace(*input.buf)) @@ -763,7 +772,16 @@ static int batch_objects(struct batch_options *opt) goto cleanup; } - while (strbuf_getline(&input, stdin) != EOF) { + while (1) { + int ret; + if (opt->nul_terminated) + ret = strbuf_getline_nul(&input, stdin); + else + ret = strbuf_getline(&input, stdin); + + if (ret == EOF) + break; + if (data.split_on_whitespace) { /* * Split at first whitespace, tying off the beginning @@ -866,6 +884,7 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix) N_("like --batch, but don't emit <contents>"), PARSE_OPT_OPTARG | PARSE_OPT_NONEG, batch_option_callback), + OPT_BOOL('z', NULL, &batch.nul_terminated, N_("stdin is NUL-terminated")), OPT_CALLBACK_F(0, "batch-command", &batch, N_("format"), N_("read commands from stdin"), PARSE_OPT_OPTARG | PARSE_OPT_NONEG, @@ -921,6 +940,9 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix) else if (batch.all_objects) usage_msg_optf(_("'%s' requires a batch mode"), usage, options, "--batch-all-objects"); + else if (batch.nul_terminated) + usage_msg_optf(_("'%s' requires a batch mode"), usage, options, + "-z"); /* Batch defaults */ if (batch.buffer_output < 0) |