As part of the ongoing effort to consolidate reference handling,
introduce a new `exists` subcommand. This command provides the same
functionality and exit-code behavior as `git show-ref --exists`, serving
as its modern replacement.
The logic for `show-ref --exists` is minimal. Rather than creating a
shared helper function which would be overkill for ~20 lines of code,
its implementation is intentionally duplicated here. This contrasts with
`git refs list`, where sharing the larger implementation of
`for-each-ref` was necessary.
Documentation for the new subcommand is also added to the `git-refs(1)`
man page.
Mentored-by: Patrick Steinhardt <ps@xxxxxx>
Mentored-by: shejialuo <shejialuo@xxxxxxxxx>
Signed-off-by: Meet Soni <meetsoni3017@xxxxxxxxx>
---
Documentation/git-refs.adoc | 7 ++++++
builtin/refs.c | 48 +++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)
diff --git a/Documentation/git-refs.adoc b/Documentation/git-refs.adoc
index d462953fb5..bfa9b3ea2d 100644
--- a/Documentation/git-refs.adoc
+++ b/Documentation/git-refs.adoc
@@ -18,6 +18,7 @@ git refs list [--count=<count>] [--shell|--perl|--python|--tcl]
[--contains[=<object>]] [--no-contains[=<object>]]
[(--exclude=<pattern>)...] [--start-after=<marker>]
[ --stdin | (<pattern>...)]
+git refs exists <ref>
DESCRIPTION
-----------
@@ -38,6 +39,12 @@ list::
formatting, and sorting. This subcommand is an alias for
linkgit:git-for-each-ref[1] and offers identical functionality.
+exists::
+ Check whether the given reference exists. Returns an exit code of 0 if
+ it does, 2 if it is missing, and 1 in case looking up the reference
+ failed with an error other than the reference being missing. This does
+ not verify whether the reference resolves to an actual object.
+
OPTIONS
-------
diff --git a/builtin/refs.c b/builtin/refs.c
index 76224feba4..617d8ab138 100644
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -7,6 +7,7 @@
#include "strbuf.h"
#include "worktree.h"
#include "for-each-ref.h"
+#include "refs/refs-internal.h"
#define REFS_MIGRATE_USAGE \
N_("git refs migrate --ref-format=<format> [--no-reflog] [--dry-run]")
@@ -14,6 +15,9 @@
#define REFS_VERIFY_USAGE \
N_("git refs verify [--strict] [--verbose]")
+#define REFS_EXISTS_USAGE \
+ N_("git refs exists <ref>")
+
static int cmd_refs_migrate(int argc, const char **argv, const char *prefix,
struct repository *repo UNUSED)
{
@@ -113,6 +117,48 @@ static int cmd_refs_list(int argc, const char **argv, const char *prefix,
return for_each_ref_core(argc, argv, prefix, repo, refs_list_usage);
}
+static int cmd_refs_exists(int argc, const char **argv, const char *prefix,
+ struct repository *repo UNUSED)
+{
+ struct strbuf unused_referent = STRBUF_INIT;
+ struct object_id unused_oid;
+ unsigned int unused_type;
+ int failure_errno = 0;
+ const char *ref;
+
+ const char * const exists_usage[] = {
+ REFS_EXISTS_USAGE,
+ NULL,
+ };
+ struct option options[] = {
+ OPT_END(),
+ };
+
+ argc = parse_options(argc, argv, prefix, options, exists_usage, 0);
+ if (!argc)
+ die("'git refs exists' requires a reference");
+
+ ref = *argv++;
+ if (*argv)
+ die("'git refs exists' requires exactly one reference");
+
+ if (refs_read_raw_ref(get_main_ref_store(the_repository), ref,
+ &unused_oid, &unused_referent, &unused_type,
+ &failure_errno)) {
+ if (failure_errno == ENOENT || failure_errno == EISDIR) {
+ error(_("reference does not exist"));
+ return 2;
+ } else {
+ errno = failure_errno;
+ error_errno(_("failed to look up reference"));
+ return 1;
+ }
+ }
+
+ strbuf_release(&unused_referent);
+ return 0;
+}
+
int cmd_refs(int argc,
const char **argv,
const char *prefix,
@@ -122,6 +168,7 @@ int cmd_refs(int argc,
REFS_MIGRATE_USAGE,
REFS_VERIFY_USAGE,
"git refs list " COMMON_USAGE_FOR_EACH_REF,
+ REFS_EXISTS_USAGE,
NULL,
};
parse_opt_subcommand_fn *fn = NULL;
@@ -129,6 +176,7 @@ int cmd_refs(int argc,
OPT_SUBCOMMAND("migrate", &fn, cmd_refs_migrate),
OPT_SUBCOMMAND("verify", &fn, cmd_refs_verify),
OPT_SUBCOMMAND("list", &fn, cmd_refs_list),
+ OPT_SUBCOMMAND("exists", &fn, cmd_refs_exists),
OPT_END(),
};
--
2.34.1
