/*
* libgit2 "tag" example - shows how to list, create and delete tags
*
* Written by the libgit2 contributors
*
* To the extent possible under law, the author(s) have dedicated all copyright
* and related and neighboring rights to this software to the public domain
* worldwide. This software is distributed without any warranty.
*
* You should have received a copy of the CC0 Public Domain Dedication along
* with this software. If not, see
* <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include "common.h"
/**
* The following example partially reimplements the `git tag` command
* and some of its options.
*
* These commands should work:
* - Tag name listing (`tag`)
* - Filtered tag listing with messages (`tag -n3 -l "v0.1*"`)
* - Lightweight tag creation (`tag test v0.18.0`)
* - Tag creation (`tag -a -m "Test message" test v0.18.0`)
* - Tag deletion (`tag -d test`)
*
* The command line parsing logic is simplified and doesn't handle
* all of the use cases.
*/
/** tag_options represents the parsed command line options */
struct tag_options {
const char *message;
const char *pattern;
const char *tag_name;
const char *target;
int num_lines;
int force;
};
/** tag_state represents the current program state for dragging around */
typedef struct {
git_repository *repo;
struct tag_options *opts;
} tag_state;
/** An action to execute based on the command line arguments */
typedef void (*tag_action)(tag_state *state);
typedef struct args_info args_info;
static void check(int result, const char *message)
{
if (result) fatal(message, NULL);
}
/** Tag listing: Print individual message lines */
static void print_list_lines(const char *message, const tag_state *state)
{
const char *msg = message;
int num = state->opts->num_lines - 1;
if (!msg) return;
/** first line - headline */
while(*msg && *msg != '\n') printf("%c", *msg++);
/** skip over new lines */
while(*msg && *msg == '\n') msg++;
printf("\n");
/** print just headline? */
if (num == 0) return;
if (*msg && msg[1]) printf("\n");
/** print individual commit/tag lines */
while (*msg && num-- >= 2) {
printf(" ");
while (*msg && *msg != '\n') printf("%c", *msg++);
/** handle consecutive new lines */
if (*msg && *msg == '\n' && msg[1] == '\n') {
num--;
printf("\n");
}
while(*msg && *msg == '\n') msg++;
printf("\n");
}
}
/** Tag listing: Print an actual tag object */
static void print_tag(git_tag *tag, const tag_state *state)
{
printf("%-16s", git_tag_name(tag));
if (state->opts->num_lines) {
const char *msg = git_tag_message(tag);
print_list_lines(msg, state);
} else {
printf("\n");
}
}
/** Tag listing: Print a commit (target of a lightweight tag) */
static void print_commit(git_commit *commit, const char *name,
const tag_state *state)
{
printf("%-16s", name);
if (state->opts->num_lines) {
const char *msg = git_commit_message(commit);
print_list_lines(msg, state);
} else {
printf("\n");
}
}
/** Tag listing: Fallback, should not happen */
static void print_name(const char *name)
{
printf("%s\n", name);
}
/** Tag listing: Lookup tags based on ref name and dispatch to print */
static int each_tag(const char *name, tag_state *state)
{
git_repository *repo = state->repo;
git_object *obj;
check_lg2(git_revparse_single(&obj, repo, name),
"Failed to lookup rev", name);
switch (git_object_type(obj)) {
case GIT_OBJECT_TAG:
print_tag((git_tag *) obj, state);
break;
case GIT_OBJECT_COMMIT:
print_commit((git_commit *) obj, name, state);
break;
default:
print_name(name);
}
git_object_free(obj);
return 0;
}
static void action_list_tags(tag_state *state)
{
const char *pattern = state->opts->pattern;
git_strarray tag_names = {0};
size_t i;
check_lg2(git_tag_list_match(&tag_names, pattern ? pattern : "*", state->repo),
"Unable to get list of tags", NULL);
for(i = 0; i < tag_names.count; i++) {
each_tag(tag_names.strings[i], state);
}
git_strarray_dispose(&tag_names);
}
static void action_delete_tag(tag_state *state)
{
struct tag_options *opts = state->opts;
git_object *obj;
git_buf abbrev_oid = {0};
check(!opts->tag_name, "Name required");
check_lg2(git_revparse_single(&obj, state->repo, opts->tag_name),
"Failed to lookup rev", opts->tag_name);
check_lg2(git_object_short_id(&abbrev_oid, obj),
"Unable to get abbreviated OID", opts->tag_name);
check_lg2(git_tag_delete(state->repo, opts->tag_name),
"Unable to delete tag", opts->tag_name);
printf("Deleted tag '%s' (was %s)\n", opts->tag_name, abbrev_oid.ptr);
git_buf_dispose(&abbrev_oid);
git_object_free(obj);
}
static void action_create_lightweight_tag(tag_state *state)
{
git_repository *repo = state->repo;
struct tag_options *opts = state->opts;
git_oid oid;
git_object *target;
check(!opts->tag_name, "Name required");
if (!opts->target) opts->target = "HEAD";
check(!opts->target, "Target required");
check_lg2(git_revparse_single(&target, repo, opts->target),
"Unable to resolve spec", opts->target);
check_lg2(git_tag_create_lightweight(&oid, repo, opts->tag_name,
target, opts->force), "Unable to create tag", NULL);
git_object_free(target);
}
static void action_create_tag(tag_state *state)
{
git_repository *repo = state->repo;
struct tag_options *opts = state->opts;
git_signature *tagger;
git_oid oid;
git_object *target;
check(!opts->tag_name, "Name required");
check(!opts->message, "Message required");
if (!opts->target) opts->target = "HEAD";
check_lg2(git_revparse_single(&target, repo, opts->target),
"Unable to resolve spec", opts->target);
check_lg2(git_signature_default(&tagger, repo),
"Unable to create signature", NULL);
check_lg2(git_tag_create(&oid, repo, opts->tag_name,
target, tagger, opts->message, opts->force), "Unable to create tag", NULL);
git_object_free(target);
git_signature_free(tagger);
}
static void print_usage(void)
{
fprintf(stderr, "usage: see `git help tag`\n");
exit(1);
}
/** Parse command line arguments and choose action to run when done */
static void parse_options(tag_action *action, struct tag_options *opts, int argc, char **argv)
{
args_info args = ARGS_INFO_INIT;
*action = &action_list_tags;
for (args.pos = 1; args.pos < argc; ++args.pos) {
const char *curr = argv[args.pos];
if (curr[0] != '-') {
if (!opts->tag_name)
opts->tag_name = curr;
else if (!opts->target)
opts->target = curr;
else
print_usage();
if (*action != &action_create_tag)
*action = &action_create_lightweight_tag;
} else if (!strcmp(curr, "-n")) {
opts->num_lines = 1;
*action = &action_list_tags;
} else if (!strcmp(curr, "-a")) {
*action = &action_create_tag;
} else if (!strcmp(curr, "-f")) {
opts->force = 1;
} else if (match_int_arg(&opts->num_lines, &args, "-n", 0)) {
*action = &action_list_tags;
} else if (match_str_arg(&opts->pattern, &args, "-l")) {
*action = &action_list_tags;
} else if (match_str_arg(&opts->tag_name, &args, "-d")) {
*action = &action_delete_tag;
} else if (match_str_arg(&opts->message, &args, "-m")) {
*action = &action_create_tag;
}
}
}
/** Initialize tag_options struct */
static void tag_options_init(struct tag_options *opts)
{
memset(opts, 0, sizeof(*opts));
opts->message = NULL;
opts->pattern = NULL;
opts->tag_name = NULL;
opts->target = NULL;
opts->num_lines = 0;
opts->force = 0;
}
int lg2_tag(git_repository *repo, int argc, char **argv)
{
struct tag_options opts;
tag_action action;
tag_state state;
tag_options_init(&opts);
parse_options(&action, &opts, argc, argv);
state.repo = repo;
state.opts = &opts;
action(&state);
return 0;
}
