[thirdparty/git.git] / git.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>

#ifndef PATH_MAX
# define PATH_MAX 4096
#endif

static const char git_usage[] =
	"Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";

/* most gui terms set COLUMNS (although some don't export it) */
static int term_columns(void)
{
	char *col_string = getenv("COLUMNS");
	int n_cols = 0;

	if (col_string && (n_cols = atoi(col_string)) > 0)
		return n_cols;

	return 80;
}

static void oom(void)
{
	fprintf(stderr, "git: out of memory\n");
	exit(1);
}

static inline void mput_char(char c, unsigned int num)
{
	while(num--)
		putchar(c);
}

static struct cmdname {
	size_t len;
	char name[1];
} **cmdname;
static int cmdname_alloc, cmdname_cnt;

static void add_cmdname(const char *name, int len)
{
	struct cmdname *ent;
	if (cmdname_alloc <= cmdname_cnt) {
		cmdname_alloc = cmdname_alloc + 200;
		cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
		if (!cmdname)
			oom();
	}
	ent = malloc(sizeof(*ent) + len);
	if (!ent)
		oom();
	ent->len = len;
	memcpy(ent->name, name, len);
	ent->name[len] = 0;
	cmdname[cmdname_cnt++] = ent;
}

static int cmdname_compare(const void *a_, const void *b_)
{
	struct cmdname *a = *(struct cmdname **)a_;
	struct cmdname *b = *(struct cmdname **)b_;
	return strcmp(a->name, b->name);
}

static void pretty_print_string_list(struct cmdname **cmdname, int longest)
{
	int cols = 1;
	int space = longest + 1; /* min 1 SP between words */
	int max_cols = term_columns() - 1; /* don't print *on* the edge */
	int i;

	if (space < max_cols)
		cols = max_cols / space;

	qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);

	for (i = 0; i < cmdname_cnt; ) {
		int c;
		printf("  ");

		for (c = cols; c && i < cmdname_cnt; i++) {
			printf("%s", cmdname[i]->name);

			if (--c)
				mput_char(' ', space - cmdname[i]->len);
		}
		putchar('\n');
	}
}

static void list_commands(const char *exec_path, const char *pattern)
{
	unsigned int longest = 0;
	char path[PATH_MAX];
	int dirlen;
	DIR *dir = opendir(exec_path);
	struct dirent *de;

	if (!dir) {
		fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
		exit(1);
	}

	dirlen = strlen(exec_path);
	if (PATH_MAX - 20 < dirlen) {
		fprintf(stderr, "git: insanely long exec-path '%s'\n",
			exec_path);
		exit(1);
	}

	memcpy(path, exec_path, dirlen);
	path[dirlen++] = '/';

	while ((de = readdir(dir)) != NULL) {
		struct stat st;
		int entlen;

		if (strncmp(de->d_name, "git-", 4))
			continue;
		strcpy(path+dirlen, de->d_name);
		if (stat(path, &st) || /* stat, not lstat */
		    !S_ISREG(st.st_mode) ||
		    !(st.st_mode & S_IXUSR))
			continue;

		entlen = strlen(de->d_name);
		if (4 < entlen && !strcmp(de->d_name + entlen - 4, ".exe"))
			entlen -= 4;

		if (longest < entlen)
			longest = entlen;

		add_cmdname(de->d_name + 4, entlen-4);
	}
	closedir(dir);

	printf("git commands available in '%s'\n", exec_path);
	printf("----------------------------");
	mput_char('-', strlen(exec_path));
	putchar('\n');
	pretty_print_string_list(cmdname, longest - 4);
	putchar('\n');
}

#ifdef __GNUC__
static void usage(const char *exec_path, const char *fmt, ...)
	__attribute__((__format__(__printf__, 2, 3), __noreturn__));
#endif
static void usage(const char *exec_path, const char *fmt, ...)
{
	if (fmt) {
		va_list ap;

		va_start(ap, fmt);
		printf("git: ");
		vprintf(fmt, ap);
		va_end(ap);
		putchar('\n');
	}
	else
		puts(git_usage);

	putchar('\n');

	if(exec_path)
		list_commands(exec_path, "git-*");

	exit(1);
}

static void prepend_to_path(const char *dir, int len)
{
	char *path, *old_path = getenv("PATH");
	int path_len = len;

	if (!old_path)
		old_path = "/usr/local/bin:/usr/bin:/bin";

	path_len = len + strlen(old_path) + 1;

	path = malloc(path_len + 1);
	path[path_len + 1] = '\0';

	memcpy(path, dir, len);
	path[len] = ':';
	memcpy(path + len + 1, old_path, path_len - len);

	setenv("PATH", path, 1);
}

static void show_man_page(char *git_cmd)
{
	char *page;

	if (!strncmp(git_cmd, "git", 3))
		page = git_cmd;
	else {
		int page_len = strlen(git_cmd) + 4;

		page = malloc(page_len + 1);
		strcpy(page, "git-");
		strcpy(page + 4, git_cmd);
		page[page_len] = 0;
	}

	execlp("man", "man", page, NULL);
}

int main(int argc, char **argv, char **envp)
{
	char git_command[PATH_MAX + 1];
	char wd[PATH_MAX + 1];
	int i, len, show_help = 0;
	char *exec_path = getenv("GIT_EXEC_PATH");

	getcwd(wd, PATH_MAX);

	if (!exec_path)
		exec_path = GIT_EXEC_PATH;

	for (i = 1; i < argc; i++) {
		char *arg = argv[i];

		if (strncmp(arg, "--", 2))
			break;

		arg += 2;

		if (!strncmp(arg, "exec-path", 9)) {
			arg += 9;
			if (*arg == '=')
				exec_path = arg + 1;
			else {
				puts(exec_path);
				exit(0);
			}
		}
		else if (!strcmp(arg, "version")) {
			printf("git version %s\n", GIT_VERSION);
			exit(0);
		}
		else if (!strcmp(arg, "help"))
			show_help = 1;
		else if (!show_help)
			usage(NULL, NULL);
	}

	if (i >= argc || show_help) {
		if (i >= argc)
			usage(exec_path, NULL);

		show_man_page(argv[i]);
	}

	if (*exec_path != '/') {
		if (!getcwd(git_command, sizeof(git_command))) {
			fprintf(stderr,
				"git: cannot determine current directory");
			exit(1);
		}
		len = strlen(git_command);

		/* Trivial cleanup */
		while (!strncmp(exec_path, "./", 2)) {
			exec_path += 2;
			while (*exec_path == '/')
				exec_path++;
		}
		snprintf(git_command + len, sizeof(git_command) - len,
			 "/%s", exec_path);
	}
	else
		strcpy(git_command, exec_path);
	len = strlen(git_command);
	prepend_to_path(git_command, len);

	len += snprintf(git_command + len, sizeof(git_command) - len,
			"/git-%s", argv[i]);
	if (sizeof(git_command) <= len) {
		fprintf(stderr, "git: command name given is too long (%d)\n", len);
		exit(1);
	}

	/* execve() can only ever return if it fails */
	execve(git_command, &argv[i], envp);

	if (errno == ENOENT)
		usage(exec_path, "'%s' is not a git-command", argv[i]);

	fprintf(stderr, "Failed to run command '%s': %s\n",
		git_command, strerror(errno));

	return 1;
}
Commit	Line	Data
8e49d503	1	#include <stdio.h>
7dbc2c04 JH	2	#include <sys/types.h>
	3	#include <sys/stat.h>
	4	#include <dirent.h>
8e49d503 AE	5	#include <unistd.h>
	6	#include <stdlib.h>
	7	#include <string.h>
	8	#include <errno.h>
	9	#include <limits.h>
	10	#include <stdarg.h>
8e49d503 AE	11
	12	#ifndef PATH_MAX
	13	# define PATH_MAX 4096
	14	#endif
	15
	16	static const char git_usage[] =
	17	"Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
	18
8e49d503 AE	19	/* most gui terms set COLUMNS (although some don't export it) */
	20	static int term_columns(void)
	21	{
	22	char *col_string = getenv("COLUMNS");
	23	int n_cols = 0;
	24
	25	if (col_string && (n_cols = atoi(col_string)) > 0)
	26	return n_cols;
	27
	28	return 80;
	29	}
	30
7dbc2c04 JH	31	static void oom(void)
	32	{
	33	fprintf(stderr, "git: out of memory\n");
	34	exit(1);
	35	}
	36
8e49d503 AE	37	static inline void mput_char(char c, unsigned int num)
	38	{
	39	while(num--)
	40	putchar(c);
	41	}
	42
7dbc2c04 JH	43	static struct cmdname {
	44	size_t len;
	45	char name[1];
	46	} **cmdname;
	47	static int cmdname_alloc, cmdname_cnt;
	48
	49	static void add_cmdname(const char *name, int len)
	50	{
	51	struct cmdname *ent;
	52	if (cmdname_alloc <= cmdname_cnt) {
	53	cmdname_alloc = cmdname_alloc + 200;
	54	cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
	55	if (!cmdname)
	56	oom();
	57	}
	58	ent = malloc(sizeof(*ent) + len);
	59	if (!ent)
	60	oom();
	61	ent->len = len;
f9039f30 JH	62	memcpy(ent->name, name, len);
f9039f30 JH	63	ent->name[len] = 0;
7dbc2c04 JH	64	cmdname[cmdname_cnt++] = ent;
	65	}
	66
	67	static int cmdname_compare(const void a_, const void b_)
	68	{
	69	struct cmdname a = (struct cmdname **)a_;
	70	struct cmdname b = (struct cmdname **)b_;
	71	return strcmp(a->name, b->name);
	72	}
	73
	74	static void pretty_print_string_list(struct cmdname **cmdname, int longest)
8e49d503 AE	75	{
	76	int cols = 1;
	77	int space = longest + 1; /* min 1 SP between words */
	78	int max_cols = term_columns() - 1; /* don't print on the edge */
7dbc2c04	79	int i;
8e49d503 AE	80
	81	if (space < max_cols)
	82	cols = max_cols / space;
	83
7dbc2c04 JH	84	qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
	85
	86	for (i = 0; i < cmdname_cnt; ) {
8e49d503 AE	87	int c;
	88	printf(" ");
	89
7dbc2c04 JH	90	for (c = cols; c && i < cmdname_cnt; i++) {
7dbc2c04 JH	91	printf("%s", cmdname[i]->name);
8e49d503 AE	92
8e49d503 AE	93	if (--c)
7dbc2c04	94	mput_char(' ', space - cmdname[i]->len);
8e49d503 AE	95	}
	96	putchar('\n');
	97	}
	98	}
	99
	100	static void list_commands(const char exec_path, const char pattern)
	101	{
7dbc2c04 JH	102	unsigned int longest = 0;
	103	char path[PATH_MAX];
	104	int dirlen;
	105	DIR *dir = opendir(exec_path);
	106	struct dirent *de;
	107
	108	if (!dir) {
	109	fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
8e49d503 AE	110	exit(1);
	111	}
	112
7dbc2c04 JH	113	dirlen = strlen(exec_path);
	114	if (PATH_MAX - 20 < dirlen) {
	115	fprintf(stderr, "git: insanely long exec-path '%s'\n",
	116	exec_path);
8e49d503 AE	117	exit(1);
	118	}
	119
7dbc2c04 JH	120	memcpy(path, exec_path, dirlen);
	121	path[dirlen++] = '/';
	122
	123	while ((de = readdir(dir)) != NULL) {
	124	struct stat st;
	125	int entlen;
8e49d503	126
7dbc2c04 JH	127	if (strncmp(de->d_name, "git-", 4))
	128	continue;
	129	strcpy(path+dirlen, de->d_name);
	130	if (stat(path, &st) \|\| /* stat, not lstat */
	131	!S_ISREG(st.st_mode) \|\|
	132	!(st.st_mode & S_IXUSR))
8e49d503 AE	133	continue;
8e49d503 AE	134
7dbc2c04	135	entlen = strlen(de->d_name);
f9039f30 JH	136	if (4 < entlen && !strcmp(de->d_name + entlen - 4, ".exe"))
f9039f30 JH	137	entlen -= 4;
8e49d503	138
7dbc2c04 JH	139	if (longest < entlen)
	140	longest = entlen;
	141
	142	add_cmdname(de->d_name + 4, entlen-4);
8e49d503	143	}
7dbc2c04	144	closedir(dir);
8e49d503 AE	145
	146	printf("git commands available in '%s'\n", exec_path);
	147	printf("----------------------------");
	148	mput_char('-', strlen(exec_path));
	149	putchar('\n');
7dbc2c04	150	pretty_print_string_list(cmdname, longest - 4);
8e49d503 AE	151	putchar('\n');
	152	}
	153
	154	#ifdef __GNUC__
	155	static void usage(const char exec_path, const char fmt, ...)
	156	__attribute__((__format__(__printf__, 2, 3), __noreturn__));
	157	#endif
	158	static void usage(const char exec_path, const char fmt, ...)
	159	{
	160	if (fmt) {
	161	va_list ap;
	162
	163	va_start(ap, fmt);
	164	printf("git: ");
	165	vprintf(fmt, ap);
	166	va_end(ap);
	167	putchar('\n');
	168	}
	169	else
	170	puts(git_usage);
	171
	172	putchar('\n');
	173
	174	if(exec_path)
	175	list_commands(exec_path, "git-*");
	176
	177	exit(1);
	178	}
	179
	180	static void prepend_to_path(const char *dir, int len)
	181	{
	182	char path, old_path = getenv("PATH");
	183	int path_len = len;
	184
	185	if (!old_path)
7dbc2c04	186	old_path = "/usr/local/bin:/usr/bin:/bin";
8e49d503 AE	187
	188	path_len = len + strlen(old_path) + 1;
	189
	190	path = malloc(path_len + 1);
	191	path[path_len + 1] = '\0';
	192
	193	memcpy(path, dir, len);
	194	path[len] = ':';
	195	memcpy(path + len + 1, old_path, path_len - len);
	196
	197	setenv("PATH", path, 1);
	198	}
	199
97fc6c5f AE	200	static void show_man_page(char *git_cmd)
	201	{
	202	char *page;
	203
	204	if (!strncmp(git_cmd, "git", 3))
	205	page = git_cmd;
	206	else {
	207	int page_len = strlen(git_cmd) + 4;
	208
	209	page = malloc(page_len + 1);
	210	strcpy(page, "git-");
	211	strcpy(page + 4, git_cmd);
	212	page[page_len] = 0;
	213	}
	214
7dbc2c04	215	execlp("man", "man", page, NULL);
97fc6c5f AE	216	}
97fc6c5f AE	217
8e49d503 AE	218	int main(int argc, char argv, char envp)
	219	{
	220	char git_command[PATH_MAX + 1];
	221	char wd[PATH_MAX + 1];
	222	int i, len, show_help = 0;
	223	char *exec_path = getenv("GIT_EXEC_PATH");
	224
	225	getcwd(wd, PATH_MAX);
	226
	227	if (!exec_path)
	228	exec_path = GIT_EXEC_PATH;
	229
	230	for (i = 1; i < argc; i++) {
	231	char *arg = argv[i];
	232
	233	if (strncmp(arg, "--", 2))
	234	break;
	235
	236	arg += 2;
	237
	238	if (!strncmp(arg, "exec-path", 9)) {
	239	arg += 9;
	240	if (*arg == '=')
	241	exec_path = arg + 1;
	242	else {
	243	puts(exec_path);
	244	exit(0);
	245	}
	246	}
	247	else if (!strcmp(arg, "version")) {
	248	printf("git version %s\n", GIT_VERSION);
	249	exit(0);
	250	}
	251	else if (!strcmp(arg, "help"))
	252	show_help = 1;
	253	else if (!show_help)
	254	usage(NULL, NULL);
	255	}
	256
97fc6c5f AE	257	if (i >= argc \|\| show_help) {
	258	if (i >= argc)
	259	usage(exec_path, NULL);
	260
	261	show_man_page(argv[i]);
	262	}
8e49d503	263
7dbc2c04 JH	264	if (*exec_path != '/') {
	265	if (!getcwd(git_command, sizeof(git_command))) {
	266	fprintf(stderr,
	267	"git: cannot determine current directory");
	268	exit(1);
	269	}
	270	len = strlen(git_command);
8e49d503	271
7dbc2c04 JH	272	/* Trivial cleanup */
	273	while (!strncmp(exec_path, "./", 2)) {
	274	exec_path += 2;
	275	while (*exec_path == '/')
874fbc33	276	exec_path++;
7dbc2c04 JH	277	}
	278	snprintf(git_command + len, sizeof(git_command) - len,
	279	"/%s", exec_path);
	280	}
	281	else
	282	strcpy(git_command, exec_path);
8e49d503 AE	283	len = strlen(git_command);
	284	prepend_to_path(git_command, len);
	285
10b15b86 AR	286	len += snprintf(git_command + len, sizeof(git_command) - len,
	287	"/git-%s", argv[i]);
	288	if (sizeof(git_command) <= len) {
	289	fprintf(stderr, "git: command name given is too long (%d)\n", len);
	290	exit(1);
	291	}
8e49d503 AE	292
	293	/* execve() can only ever return if it fails */
	294	execve(git_command, &argv[i], envp);
10b15b86 AR	295
	296	if (errno == ENOENT)
	297	usage(exec_path, "'%s' is not a git-command", argv[i]);
	298
	299	fprintf(stderr, "Failed to run command '%s': %s\n",
	300	git_command, strerror(errno));
8e49d503 AE	301
	302	return 1;
	303	}