[thirdparty/git.git] / config.c

/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 * Copyright (C) Johannes Schindelin, 2005
 *
 */
#include "cache.h"
#include <regex.h>

#define MAXNAME (256)

static FILE *config_file;
static const char *config_file_name;
static int config_linenr;
static int get_next_char(void)
{
	int c;
	FILE *f;

	c = '\n';
	if ((f = config_file) != NULL) {
		c = fgetc(f);
		if (c == '\r') {
			/* DOS like systems */
			c = fgetc(f);
			if (c != '\n') {
				ungetc(c, f);
				c = '\r';
			}
		}
		if (c == '\n')
			config_linenr++;
		if (c == EOF) {
			config_file = NULL;
			c = '\n';
		}
	}
	return c;
}

static char *parse_value(void)
{
	static char value[1024];
	int quote = 0, comment = 0, len = 0, space = 0;

	for (;;) {
		int c = get_next_char();
		if (len >= sizeof(value))
			return NULL;
		if (c == '\n') {
			if (quote)
				return NULL;
			value[len] = 0;
			return value;
		}
		if (comment)
			continue;
		if (isspace(c) && !quote) {
			space = 1;
			continue;
		}
		if (space) {
			if (len)
				value[len++] = ' ';
			space = 0;
		}
		if (c == '\\') {
			c = get_next_char();
			switch (c) {
			case '\n':
				continue;
			case 't':
				c = '\t';
				break;
			case 'b':
				c = '\b';
				break;
			case 'n':
				c = '\n';
				break;
			/* Some characters escape as themselves */
			case '\\': case '"':
				break;
			/* Reject unknown escape sequences */
			default:
				return NULL;
			}
			value[len++] = c;
			continue;
		}
		if (c == '"') {
			quote = 1-quote;
			continue;
		}
		if (!quote) {
			if (c == ';' || c == '#') {
				comment = 1;
				continue;
			}
		}
		value[len++] = c;
	}
}

static int get_value(config_fn_t fn, char *name, unsigned int len)
{
	int c;
	char *value;

	/* Get the full name */
	for (;;) {
		c = get_next_char();
		if (c == EOF)
			break;
		if (!isalnum(c))
			break;
		name[len++] = tolower(c);
		if (len >= MAXNAME)
			return -1;
	}
	name[len] = 0;
	while (c == ' ' || c == '\t')
		c = get_next_char();

	value = NULL;
	if (c != '\n') {
		if (c != '=')
			return -1;
		value = parse_value();
		if (!value)
			return -1;
	}
	return fn(name, value);
}

static int get_base_var(char *name)
{
	int baselen = 0;

	for (;;) {
		int c = get_next_char();
		if (c == EOF)
			return -1;
		if (c == ']')
			return baselen;
		if (!isalnum(c) && c != '.')
			return -1;
		if (baselen > MAXNAME / 2)
			return -1;
		name[baselen++] = tolower(c);
	}
}

static int git_parse_file(config_fn_t fn)
{
	int comment = 0;
	int baselen = 0;
	static char var[MAXNAME];

	for (;;) {
		int c = get_next_char();
		if (c == '\n') {
			/* EOF? */
			if (!config_file)
				return 0;
			comment = 0;
			continue;
		}
		if (comment || isspace(c))
			continue;
		if (c == '#' || c == ';') {
			comment = 1;
			continue;
		}
		if (c == '[') {
			baselen = get_base_var(var);
			if (baselen <= 0)
				break;
			var[baselen++] = '.';
			var[baselen] = 0;
			continue;
		}
		if (!isalpha(c))
			break;
		var[baselen] = tolower(c);
		if (get_value(fn, var, baselen+1) < 0)
			break;
	}
	die("bad config file line %d in %s", config_linenr, config_file_name);
}

int git_config_int(const char *name, const char *value)
{
	if (value && *value) {
		char *end;
		int val = strtol(value, &end, 0);
		if (!*end)
			return val;
	}
	die("bad config value for '%s' in %s", name, config_file_name);
}

int git_config_bool(const char *name, const char *value)
{
	if (!value)
		return 1;
	if (!*value)
		return 0;
	if (!strcasecmp(value, "true"))
		return 1;
	if (!strcasecmp(value, "false"))
		return 0;
	return git_config_int(name, value) != 0;
}

int git_default_config(const char *var, const char *value)
{
	/* This needs a better name */
	if (!strcmp(var, "core.filemode")) {
		trust_executable_bit = git_config_bool(var, value);
		return 0;
	}

	if (!strcmp(var, "core.ignorestat")) {
		assume_unchanged = git_config_bool(var, value);
		return 0;
	}

	if (!strcmp(var, "core.symrefsonly")) {
		only_use_symrefs = git_config_bool(var, value);
		return 0;
	}

	if (!strcmp(var, "user.name")) {
		strncpy(git_default_name, value, sizeof(git_default_name));
		return 0;
	}

	if (!strcmp(var, "user.email")) {
		strncpy(git_default_email, value, sizeof(git_default_email));
		return 0;
	}

	if (!strcmp(var, "i18n.commitencoding")) {
		strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
		return 0;
	}

	/* Add other config variables here.. */
	return 0;
}

int git_config_from_file(config_fn_t fn, const char *filename)
{
	int ret;
	FILE *f = fopen(filename, "r");

	ret = -1;
	if (f) {
		config_file = f;
		config_file_name = filename;
		config_linenr = 1;
		ret = git_parse_file(fn);
		fclose(f);
		config_file_name = NULL;
	}
	return ret;
}

int git_config(config_fn_t fn)
{
	return git_config_from_file(fn, git_path("config"));
}

/*
 * Find all the stuff for git_config_set() below.
 */

#define MAX_MATCHES 512

static struct {
	int baselen;
	char* key;
	int do_not_match;
	regex_t* value_regex;
	int multi_replace;
	off_t offset[MAX_MATCHES];
	enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
	int seen;
} store;

static int matches(const char* key, const char* value)
{
	return !strcmp(key, store.key) &&
		(store.value_regex == NULL ||
		 (store.do_not_match ^
		  !regexec(store.value_regex, value, 0, NULL, 0)));
}

static int store_aux(const char* key, const char* value)
{
	switch (store.state) {
	case KEY_SEEN:
		if (matches(key, value)) {
			if (store.seen == 1 && store.multi_replace == 0) {
				fprintf(stderr,
					"Warning: %s has multiple values\n",
					key);
			} else if (store.seen >= MAX_MATCHES) {
				fprintf(stderr, "Too many matches\n");
				return 1;
			}

			store.offset[store.seen] = ftell(config_file);
			store.seen++;
		}
		break;
	case SECTION_SEEN:
		if (strncmp(key, store.key, store.baselen+1)) {
			store.state = SECTION_END_SEEN;
			break;
		} else
			/* do not increment matches: this is no match */
			store.offset[store.seen] = ftell(config_file);
		/* fallthru */
	case SECTION_END_SEEN:
	case START:
		if (matches(key, value)) {
			store.offset[store.seen] = ftell(config_file);
			store.state = KEY_SEEN;
			store.seen++;
		} else if(!strncmp(key, store.key, store.baselen))
			store.state = SECTION_SEEN;
	}
	return 0;
}

static void store_write_section(int fd, const char* key)
{
	write(fd, "[", 1);
	write(fd, key, store.baselen);
	write(fd, "]\n", 2);
}

static void store_write_pair(int fd, const char* key, const char* value)
{
	int i;

	write(fd, "\t", 1);
	write(fd, key+store.baselen+1,
		strlen(key+store.baselen+1));
	write(fd, " = ", 3);
	for (i = 0; value[i]; i++)
		switch (value[i]) {
		case '\n': write(fd, "\\n", 2); break;
		case '\t': write(fd, "\\t", 2); break;
		case '"': case '\\': write(fd, "\\", 1);
		default: write(fd, value+i, 1);
	}
	write(fd, "\n", 1);
}

static int find_beginning_of_line(const char* contents, int size,
	int offset_, int* found_bracket)
{
	int equal_offset = size, bracket_offset = size;
	int offset;

	for (offset = offset_-2; offset > 0 
			&& contents[offset] != '\n'; offset--)
		switch (contents[offset]) {
			case '=': equal_offset = offset; break;
			case ']': bracket_offset = offset; break;
		}
	if (bracket_offset < equal_offset) {
		*found_bracket = 1;
		offset = bracket_offset+1;
	} else
		offset++;

	return offset;
}

int git_config_set(const char* key, const char* value)
{
	return git_config_set_multivar(key, value, NULL, 0);
}

/*
 * If value==NULL, unset in (remove from) config,
 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 *     else all matching key/values (regardless how many) are removed,
 *     before the new pair is written.
 *
 * Returns 0 on success.
 *
 * This function does this:
 *
 * - it locks the config file by creating ".git/config.lock"
 *
 * - it then parses the config using store_aux() as validator to find
 *   the position on the key/value pair to replace. If it is to be unset,
 *   it must be found exactly once.
 *
 * - the config file is mmap()ed and the part before the match (if any) is
 *   written to the lock file, then the changed part and the rest.
 *
 * - the config file is removed and the lock file rename()d to it.
 *
 */
int git_config_set_multivar(const char* key, const char* value,
	const char* value_regex, int multi_replace)
{
	int i;
	int fd, in_fd;
	char* config_filename = strdup(git_path("config"));
	char* lock_file = strdup(git_path("config.lock"));
	const char* last_dot = strrchr(key, '.');

	/*
	 * Since "key" actually contains the section name and the real
	 * key name separated by a dot, we have to know where the dot is.
	 */

	if (last_dot == NULL) {	
		fprintf(stderr, "key does not contain a section: %s\n", key);
		return 2;
	}
	store.baselen = last_dot - key;

	store.multi_replace = multi_replace;

	/*
	 * Validate the key and while at it, lower case it for matching.
	 */
	store.key = (char*)malloc(strlen(key)+1);
	for (i = 0; key[i]; i++)
		if (i != store.baselen &&
				((!isalnum(key[i]) && key[i] != '.') ||
				 (i == store.baselen+1 && !isalpha(key[i])))) {
			fprintf(stderr, "invalid key: %s\n", key);
			free(store.key);
			return 1;
		} else
			store.key[i] = tolower(key[i]);
	store.key[i] = 0;

	/*
	 * The lock_file serves a purpose in addition to locking: the new
	 * contents of .git/config will be written into it.
	 */
	fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
	if (fd < 0) {
		fprintf(stderr, "could not lock config file\n");
		free(store.key);
		return -1;
	}

	/*
	 * If .git/config does not exist yet, write a minimal version.
	 */
	in_fd = open(config_filename, O_RDONLY);
	if ( in_fd < 0 ) {
		free(store.key);

		if ( ENOENT != errno ) {
			error("opening %s: %s", config_filename,
			      strerror(errno));
			close(fd);
			unlink(lock_file);
			return 3; /* same as "invalid config file" */
		}
		/* if nothing to unset, error out */
		if (value == NULL) {
			close(fd);
			unlink(lock_file);
			return 5;
		}

		store.key = (char*)key;
		store_write_section(fd, key);
		store_write_pair(fd, key, value);
	} else{
		struct stat st;
		char* contents;
		int i, copy_begin, copy_end, new_line = 0;

		if (value_regex == NULL)
			store.value_regex = NULL;
		else {
			if (value_regex[0] == '!') {
				store.do_not_match = 1;
				value_regex++;
			} else
				store.do_not_match = 0;

			store.value_regex = (regex_t*)malloc(sizeof(regex_t));
			if (regcomp(store.value_regex, value_regex,
					REG_EXTENDED)) {
				fprintf(stderr, "Invalid pattern: %s\n",
					value_regex);
				free(store.value_regex);
				return 6;
			}
		}

		store.offset[0] = 0;
		store.state = START;
		store.seen = 0;

		/*
		 * After this, store.offset will contain the *end* offset
		 * of the last match, or remain at 0 if no match was found.
		 * As a side effect, we make sure to transform only a valid
		 * existing config file.
		 */
		if (git_config(store_aux)) {
			fprintf(stderr, "invalid config file\n");
			free(store.key);
			if (store.value_regex != NULL) {
				regfree(store.value_regex);
				free(store.value_regex);
			}
			return 3;
		}

		free(store.key);
		if (store.value_regex != NULL) {
			regfree(store.value_regex);
			free(store.value_regex);
		}

		/* if nothing to unset, or too many matches, error out */
		if ((store.seen == 0 && value == NULL) ||
				(store.seen > 1 && multi_replace == 0)) {
			close(fd);
			unlink(lock_file);
			return 5;
		}

		fstat(in_fd, &st);
		contents = mmap(NULL, st.st_size, PROT_READ,
			MAP_PRIVATE, in_fd, 0);
		close(in_fd);

		if (store.seen == 0)
			store.seen = 1;

		for (i = 0, copy_begin = 0; i < store.seen; i++) {
			if (store.offset[i] == 0) {
				store.offset[i] = copy_end = st.st_size;
			} else if (store.state != KEY_SEEN) {
				copy_end = store.offset[i];
			} else
				copy_end = find_beginning_of_line(
					contents, st.st_size,
					store.offset[i]-2, &new_line);

			/* write the first part of the config */
			if (copy_end > copy_begin) {
				write(fd, contents + copy_begin,
				copy_end - copy_begin);
				if (new_line)
					write(fd, "\n", 1);
			}
			copy_begin = store.offset[i];
		}

		/* write the pair (value == NULL means unset) */
		if (value != NULL) {
			if (store.state == START)
				store_write_section(fd, key);
			store_write_pair(fd, key, value);
		}

		/* write the rest of the config */
		if (copy_begin < st.st_size)
			write(fd, contents + copy_begin,
				st.st_size - copy_begin);

		munmap(contents, st.st_size);
		unlink(config_filename);
	}

	close(fd);

	if (rename(lock_file, config_filename) < 0) {
		fprintf(stderr, "Could not rename the lock file?\n");
		return 4;
	}

	return 0;
}
Commit	Line	Data
10bea152 JS	1	/*
	2	* GIT - The information manager from hell
	3	*
	4	* Copyright (C) Linus Torvalds, 2005
	5	* Copyright (C) Johannes Schindelin, 2005
	6	*
	7	*/
17712991	8	#include "cache.h"
10bea152	9	#include <regex.h>
17712991 LT	10
	11	#define MAXNAME (256)
	12
	13	static FILE *config_file;
0dccc7dc	14	static const char *config_file_name;
17712991 LT	15	static int config_linenr;
	16	static int get_next_char(void)
	17	{
	18	int c;
	19	FILE *f;
	20
	21	c = '\n';
	22	if ((f = config_file) != NULL) {
	23	c = fgetc(f);
db2c075d JH	24	if (c == '\r') {
	25	/* DOS like systems */
	26	c = fgetc(f);
	27	if (c != '\n') {
	28	ungetc(c, f);
	29	c = '\r';
	30	}
	31	}
17712991 LT	32	if (c == '\n')
	33	config_linenr++;
	34	if (c == EOF) {
	35	config_file = NULL;
	36	c = '\n';
	37	}
	38	}
	39	return c;
	40	}
	41
	42	static char *parse_value(void)
	43	{
	44	static char value[1024];
	45	int quote = 0, comment = 0, len = 0, space = 0;
	46
	47	for (;;) {
	48	int c = get_next_char();
	49	if (len >= sizeof(value))
	50	return NULL;
	51	if (c == '\n') {
	52	if (quote)
	53	return NULL;
	54	value[len] = 0;
	55	return value;
	56	}
	57	if (comment)
	58	continue;
	59	if (isspace(c) && !quote) {
	60	space = 1;
	61	continue;
	62	}
	63	if (space) {
	64	if (len)
	65	value[len++] = ' ';
	66	space = 0;
	67	}
	68	if (c == '\\') {
	69	c = get_next_char();
	70	switch (c) {
	71	case '\n':
	72	continue;
	73	case 't':
	74	c = '\t';
	75	break;
	76	case 'b':
	77	c = '\b';
	78	break;
	79	case 'n':
	80	c = '\n';
	81	break;
5cbb401d LT	82	/* Some characters escape as themselves */
	83	case '\\': case '"':
	84	break;
	85	/* Reject unknown escape sequences */
	86	default:
	87	return NULL;
17712991 LT	88	}
	89	value[len++] = c;
	90	continue;
	91	}
	92	if (c == '"') {
	93	quote = 1-quote;
	94	continue;
	95	}
	96	if (!quote) {
	97	if (c == ';' \|\| c == '#') {
	98	comment = 1;
	99	continue;
	100	}
	101	}
	102	value[len++] = c;
	103	}
	104	}
	105
	106	static int get_value(config_fn_t fn, char *name, unsigned int len)
	107	{
	108	int c;
	109	char *value;
	110
	111	/* Get the full name */
	112	for (;;) {
	113	c = get_next_char();
	114	if (c == EOF)
	115	break;
	116	if (!isalnum(c))
	117	break;
	118	name[len++] = tolower(c);
	119	if (len >= MAXNAME)
	120	return -1;
	121	}
	122	name[len] = 0;
	123	while (c == ' ' \|\| c == '\t')
	124	c = get_next_char();
	125
	126	value = NULL;
	127	if (c != '\n') {
	128	if (c != '=')
	129	return -1;
	130	value = parse_value();
	131	if (!value)
	132	return -1;
	133	}
	134	return fn(name, value);
	135	}
	136
	137	static int get_base_var(char *name)
	138	{
	139	int baselen = 0;
	140
	141	for (;;) {
	142	int c = get_next_char();
	143	if (c == EOF)
	144	return -1;
	145	if (c == ']')
	146	return baselen;
b17e659d	147	if (!isalnum(c) && c != '.')
17712991 LT	148	return -1;
	149	if (baselen > MAXNAME / 2)
	150	return -1;
	151	name[baselen++] = tolower(c);
	152	}
	153	}
	154
	155	static int git_parse_file(config_fn_t fn)
	156	{
	157	int comment = 0;
	158	int baselen = 0;
	159	static char var[MAXNAME];
	160
	161	for (;;) {
	162	int c = get_next_char();
	163	if (c == '\n') {
	164	/* EOF? */
	165	if (!config_file)
	166	return 0;
	167	comment = 0;
	168	continue;
	169	}
	170	if (comment \|\| isspace(c))
	171	continue;
	172	if (c == '#' \|\| c == ';') {
	173	comment = 1;
	174	continue;
	175	}
	176	if (c == '[') {
	177	baselen = get_base_var(var);
	178	if (baselen <= 0)
	179	break;
	180	var[baselen++] = '.';
	181	var[baselen] = 0;
	182	continue;
	183	}
	184	if (!isalpha(c))
	185	break;
128af9d1	186	var[baselen] = tolower(c);
17712991 LT	187	if (get_value(fn, var, baselen+1) < 0)
	188	break;
	189	}
4f629539	190	die("bad config file line %d in %s", config_linenr, config_file_name);
17712991 LT	191	}
	192
	193	int git_config_int(const char name, const char value)
	194	{
	195	if (value && *value) {
	196	char *end;
	197	int val = strtol(value, &end, 0);
	198	if (!*end)
	199	return val;
	200	}
4f629539	201	die("bad config value for '%s' in %s", name, config_file_name);
17712991 LT	202	}
	203
	204	int git_config_bool(const char name, const char value)
	205	{
	206	if (!value)
	207	return 1;
	208	if (!*value)
	209	return 0;
	210	if (!strcasecmp(value, "true"))
	211	return 1;
	212	if (!strcasecmp(value, "false"))
	213	return 0;
	214	return git_config_int(name, value) != 0;
	215	}
	216
	217	int git_default_config(const char var, const char value)
	218	{
	219	/* This needs a better name */
	220	if (!strcmp(var, "core.filemode")) {
	221	trust_executable_bit = git_config_bool(var, value);
	222	return 0;
	223	}
	224
5f73076c JH	225	if (!strcmp(var, "core.ignorestat")) {
	226	assume_unchanged = git_config_bool(var, value);
	227	return 0;
	228	}
	229
f8348be3 JS	230	if (!strcmp(var, "core.symrefsonly")) {
	231	only_use_symrefs = git_config_bool(var, value);
	232	return 0;
	233	}
	234
e1b10391 LT	235	if (!strcmp(var, "user.name")) {
	236	strncpy(git_default_name, value, sizeof(git_default_name));
	237	return 0;
	238	}
	239
	240	if (!strcmp(var, "user.email")) {
	241	strncpy(git_default_email, value, sizeof(git_default_email));
	242	return 0;
	243	}
	244
4e72dcec JH	245	if (!strcmp(var, "i18n.commitencoding")) {
	246	strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
	247	return 0;
	248	}
	249
17712991 LT	250	/* Add other config variables here.. */
	251	return 0;
	252	}
	253
4f629539	254	int git_config_from_file(config_fn_t fn, const char *filename)
17712991 LT	255	{
17712991 LT	256	int ret;
4f629539	257	FILE *f = fopen(filename, "r");
17712991 LT	258
	259	ret = -1;
	260	if (f) {
	261	config_file = f;
4f629539	262	config_file_name = filename;
17712991 LT	263	config_linenr = 1;
	264	ret = git_parse_file(fn);
	265	fclose(f);
4f629539	266	config_file_name = NULL;
17712991 LT	267	}
	268	return ret;
	269	}
10bea152	270
4f629539 JH	271	int git_config(config_fn_t fn)
	272	{
	273	return git_config_from_file(fn, git_path("config"));
	274	}
	275
10bea152 JS	276	/*
	277	* Find all the stuff for git_config_set() below.
	278	*/
4ddba79d JS	279
	280	#define MAX_MATCHES 512
	281
10bea152 JS	282	static struct {
	283	int baselen;
	284	char* key;
f98d863d	285	int do_not_match;
10bea152	286	regex_t* value_regex;
4ddba79d JS	287	int multi_replace;
4ddba79d JS	288	off_t offset[MAX_MATCHES];
10bea152 JS	289	enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
	290	int seen;
	291	} store;
	292
f98d863d JS	293	static int matches(const char* key, const char* value)
	294	{
	295	return !strcmp(key, store.key) &&
	296	(store.value_regex == NULL \|\|
	297	(store.do_not_match ^
	298	!regexec(store.value_regex, value, 0, NULL, 0)));
	299	}
	300
10bea152 JS	301	static int store_aux(const char* key, const char* value)
	302	{
	303	switch (store.state) {
	304	case KEY_SEEN:
f98d863d	305	if (matches(key, value)) {
4ddba79d	306	if (store.seen == 1 && store.multi_replace == 0) {
10bea152 JS	307	fprintf(stderr,
	308	"Warning: %s has multiple values\n",
	309	key);
4ddba79d JS	310	} else if (store.seen >= MAX_MATCHES) {
	311	fprintf(stderr, "Too many matches\n");
	312	return 1;
10bea152	313	}
4ddba79d JS	314
4ddba79d JS	315	store.offset[store.seen] = ftell(config_file);
10bea152 JS	316	store.seen++;
	317	}
	318	break;
	319	case SECTION_SEEN:
	320	if (strncmp(key, store.key, store.baselen+1)) {
	321	store.state = SECTION_END_SEEN;
	322	break;
	323	} else
4ddba79d JS	324	/* do not increment matches: this is no match */
4ddba79d JS	325	store.offset[store.seen] = ftell(config_file);
10bea152 JS	326	/* fallthru */
	327	case SECTION_END_SEEN:
	328	case START:
f98d863d	329	if (matches(key, value)) {
4ddba79d	330	store.offset[store.seen] = ftell(config_file);
10bea152 JS	331	store.state = KEY_SEEN;
	332	store.seen++;
	333	} else if(!strncmp(key, store.key, store.baselen))
	334	store.state = SECTION_SEEN;
	335	}
	336	return 0;
	337	}
	338
	339	static void store_write_section(int fd, const char* key)
	340	{
	341	write(fd, "[", 1);
	342	write(fd, key, store.baselen);
	343	write(fd, "]\n", 2);
	344	}
	345
	346	static void store_write_pair(int fd, const char* key, const char* value)
	347	{
	348	int i;
	349
	350	write(fd, "\t", 1);
	351	write(fd, key+store.baselen+1,
	352	strlen(key+store.baselen+1));
	353	write(fd, " = ", 3);
	354	for (i = 0; value[i]; i++)
	355	switch (value[i]) {
	356	case '\n': write(fd, "\\n", 2); break;
	357	case '\t': write(fd, "\\t", 2); break;
	358	case '"': case '\\': write(fd, "\\", 1);
	359	default: write(fd, value+i, 1);
	360	}
	361	write(fd, "\n", 1);
	362	}
	363
4ddba79d JS	364	static int find_beginning_of_line(const char* contents, int size,
	365	int offset_, int* found_bracket)
	366	{
	367	int equal_offset = size, bracket_offset = size;
	368	int offset;
	369
	370	for (offset = offset_-2; offset > 0
	371	&& contents[offset] != '\n'; offset--)
	372	switch (contents[offset]) {
	373	case '=': equal_offset = offset; break;
	374	case ']': bracket_offset = offset; break;
	375	}
	376	if (bracket_offset < equal_offset) {
	377	*found_bracket = 1;
	378	offset = bracket_offset+1;
	379	} else
	380	offset++;
	381
	382	return offset;
	383	}
	384
10bea152 JS	385	int git_config_set(const char* key, const char* value)
10bea152 JS	386	{
4ddba79d	387	return git_config_set_multivar(key, value, NULL, 0);
10bea152 JS	388	}
	389
	390	/*
	391	* If value==NULL, unset in (remove from) config,
	392	* if value_regex!=NULL, disregard key/value pairs where value does not match.
4ddba79d JS	393	* if multi_replace==0, nothing, or only one matching key/value is replaced,
	394	* else all matching key/values (regardless how many) are removed,
	395	* before the new pair is written.
10bea152 JS	396	*
	397	* Returns 0 on success.
	398	*
	399	* This function does this:
	400	*
	401	* - it locks the config file by creating ".git/config.lock"
	402	*
	403	* - it then parses the config using store_aux() as validator to find
	404	* the position on the key/value pair to replace. If it is to be unset,
	405	* it must be found exactly once.
	406	*
	407	* - the config file is mmap()ed and the part before the match (if any) is
	408	* written to the lock file, then the changed part and the rest.
	409	*
	410	* - the config file is removed and the lock file rename()d to it.
	411	*
	412	*/
	413	int git_config_set_multivar(const char* key, const char* value,
4ddba79d	414	const char* value_regex, int multi_replace)
10bea152 JS	415	{
10bea152 JS	416	int i;
88fb958b	417	int fd, in_fd;
3a2f2bb3	418	char* config_filename = strdup(git_path("config"));
10bea152	419	char* lock_file = strdup(git_path("config.lock"));
b17e659d	420	const char* last_dot = strrchr(key, '.');
4ddba79d	421
10bea152 JS	422	/*
	423	* Since "key" actually contains the section name and the real
	424	* key name separated by a dot, we have to know where the dot is.
	425	*/
b17e659d JS	426
b17e659d JS	427	if (last_dot == NULL) {
10bea152 JS	428	fprintf(stderr, "key does not contain a section: %s\n", key);
	429	return 2;
	430	}
b17e659d JS	431	store.baselen = last_dot - key;
	432
	433	store.multi_replace = multi_replace;
10bea152 JS	434
	435	/*
	436	* Validate the key and while at it, lower case it for matching.
	437	*/
	438	store.key = (char*)malloc(strlen(key)+1);
	439	for (i = 0; key[i]; i++)
b17e659d JS	440	if (i != store.baselen &&
	441	((!isalnum(key[i]) && key[i] != '.') \|\|
	442	(i == store.baselen+1 && !isalpha(key[i])))) {
10bea152 JS	443	fprintf(stderr, "invalid key: %s\n", key);
	444	free(store.key);
	445	return 1;
	446	} else
	447	store.key[i] = tolower(key[i]);
3dd94e3b	448	store.key[i] = 0;
10bea152 JS	449
	450	/*
	451	* The lock_file serves a purpose in addition to locking: the new
	452	* contents of .git/config will be written into it.
	453	*/
	454	fd = open(lock_file, O_WRONLY \| O_CREAT \| O_EXCL, 0666);
	455	if (fd < 0) {
	456	fprintf(stderr, "could not lock config file\n");
	457	free(store.key);
	458	return -1;
	459	}
	460
	461	/*
	462	* If .git/config does not exist yet, write a minimal version.
	463	*/
88fb958b AR	464	in_fd = open(config_filename, O_RDONLY);
88fb958b AR	465	if ( in_fd < 0 ) {
10bea152 JS	466	free(store.key);
10bea152 JS	467
88fb958b AR	468	if ( ENOENT != errno ) {
	469	error("opening %s: %s", config_filename,
	470	strerror(errno));
	471	close(fd);
	472	unlink(lock_file);
	473	return 3; /* same as "invalid config file" */
	474	}
10bea152 JS	475	/* if nothing to unset, error out */
	476	if (value == NULL) {
	477	close(fd);
	478	unlink(lock_file);
	479	return 5;
	480	}
	481
	482	store.key = (char*)key;
10bea152 JS	483	store_write_section(fd, key);
	484	store_write_pair(fd, key, value);
	485	} else{
88fb958b	486	struct stat st;
10bea152	487	char* contents;
4ddba79d	488	int i, copy_begin, copy_end, new_line = 0;
10bea152 JS	489
	490	if (value_regex == NULL)
	491	store.value_regex = NULL;
	492	else {
f98d863d JS	493	if (value_regex[0] == '!') {
	494	store.do_not_match = 1;
	495	value_regex++;
	496	} else
	497	store.do_not_match = 0;
	498
10bea152 JS	499	store.value_regex = (regex_t*)malloc(sizeof(regex_t));
	500	if (regcomp(store.value_regex, value_regex,
	501	REG_EXTENDED)) {
7246ed43	502	fprintf(stderr, "Invalid pattern: %s\n",
10bea152 JS	503	value_regex);
	504	free(store.value_regex);
	505	return 6;
	506	}
	507	}
	508
4ddba79d	509	store.offset[0] = 0;
10bea152 JS	510	store.state = START;
	511	store.seen = 0;
	512
	513	/*
	514	* After this, store.offset will contain the end offset
	515	* of the last match, or remain at 0 if no match was found.
	516	* As a side effect, we make sure to transform only a valid
	517	* existing config file.
	518	*/
	519	if (git_config(store_aux)) {
	520	fprintf(stderr, "invalid config file\n");
	521	free(store.key);
	522	if (store.value_regex != NULL) {
	523	regfree(store.value_regex);
	524	free(store.value_regex);
	525	}
	526	return 3;
	527	}
	528
	529	free(store.key);
	530	if (store.value_regex != NULL) {
	531	regfree(store.value_regex);
	532	free(store.value_regex);
	533	}
	534
4ddba79d JS	535	/* if nothing to unset, or too many matches, error out */
	536	if ((store.seen == 0 && value == NULL) \|\|
	537	(store.seen > 1 && multi_replace == 0)) {
10bea152 JS	538	close(fd);
	539	unlink(lock_file);
	540	return 5;
	541	}
	542
88fb958b	543	fstat(in_fd, &st);
10bea152 JS	544	contents = mmap(NULL, st.st_size, PROT_READ,
	545	MAP_PRIVATE, in_fd, 0);
	546	close(in_fd);
	547
4ddba79d JS	548	if (store.seen == 0)
	549	store.seen = 1;
	550
	551	for (i = 0, copy_begin = 0; i < store.seen; i++) {
	552	if (store.offset[i] == 0) {
	553	store.offset[i] = copy_end = st.st_size;
	554	} else if (store.state != KEY_SEEN) {
	555	copy_end = store.offset[i];
10bea152	556	} else
4ddba79d JS	557	copy_end = find_beginning_of_line(
	558	contents, st.st_size,
	559	store.offset[i]-2, &new_line);
	560
	561	/* write the first part of the config */
	562	if (copy_end > copy_begin) {
	563	write(fd, contents + copy_begin,
	564	copy_end - copy_begin);
	565	if (new_line)
	566	write(fd, "\n", 1);
	567	}
	568	copy_begin = store.offset[i];
10bea152 JS	569	}
10bea152 JS	570
10bea152 JS	571	/* write the pair (value == NULL means unset) */
	572	if (value != NULL) {
	573	if (store.state == START)
	574	store_write_section(fd, key);
	575	store_write_pair(fd, key, value);
	576	}
	577
	578	/* write the rest of the config */
4ddba79d JS	579	if (copy_begin < st.st_size)
	580	write(fd, contents + copy_begin,
	581	st.st_size - copy_begin);
10bea152 JS	582
10bea152 JS	583	munmap(contents, st.st_size);
3a2f2bb3	584	unlink(config_filename);
10bea152 JS	585	}
	586
	587	close(fd);
	588
3a2f2bb3	589	if (rename(lock_file, config_filename) < 0) {
10bea152 JS	590	fprintf(stderr, "Could not rename the lock file?\n");
	591	return 4;
	592	}
	593
	594	return 0;
	595	}
	596
4ddba79d	597