text: /*
   * Totally braindamaged mbox splitter program.
   *
   * It just splits a mbox into a list of files: "0001" "0002" ..
   * so you can process them further from there.
   */
  #include "cache.h"
  #include "builtin.h"
  #include "string-list.h"
  #include "strbuf.h"
  
  static const char git_mailsplit_usage[] =
  "git mailsplit [-d<prec>] [-f<n>] [-b] [--keep-cr] -o<directory> [(<mbox>|<Maildir>)...]";
  
  static int is_from_line(const char *line, int len)
  {
  	const char *colon;
  
  	if (len < 20 || memcmp("From ", line, 5))
  		return 0;
  
  	colon = line + len - 2;
  	line += 5;
  	for (;;) {
  		if (colon < line)
  			return 0;
  		if (*--colon == ':')
  			break;
  	}
  
  	if (!isdigit(colon[-4]) ||
  	    !isdigit(colon[-2]) ||
  	    !isdigit(colon[-1]) ||
  	    !isdigit(colon[ 1]) ||
  	    !isdigit(colon[ 2]))
  		return 0;
  
  	/* year */
  	if (strtol(colon+3, NULL, 10) <= 90)
  		return 0;
  
  	/* Ok, close enough */
  	return 1;
  }
  
  static struct strbuf buf = STRBUF_INIT;
  static int keep_cr;
  
  /* Called with the first line (potentially partial)
   * already in buf[] -- normally that should begin with
   * the Unix "From " line.  Write it into the specified
   * file.
   */
  static int split_one(FILE *mbox, const char *name, int allow_bare)
  {
  	FILE *output = NULL;
  	int fd;
  	int status = 0;
  	int is_bare = !is_from_line(buf.buf, buf.len);
  
  	if (is_bare && !allow_bare)
  		goto corrupt;
  
  	fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
  	if (fd < 0)
  		die_errno("cannot open output file '%s'", name);
  	output = xfdopen(fd, "w");
  
  	/* Copy it out, while searching for a line that begins with
  	 * "From " and having something that looks like a date format.
  	 */
  	for (;;) {
  		if (!keep_cr && buf.len > 1 && buf.buf[buf.len-1] == '\n' &&
  			buf.buf[buf.len-2] == '\r') {
  			strbuf_setlen(&buf, buf.len-2);
  			strbuf_addch(&buf, '\n');
  		}
  
  		if (fwrite(buf.buf, 1, buf.len, output) != buf.len)
  			die_errno("cannot write output");
  
  		if (strbuf_getwholeline(&buf, mbox, '\n')) {
  			if (feof(mbox)) {
  				status = 1;
  				break;
  			}
  			die_errno("cannot read mbox");
  		}
  		if (!is_bare && is_from_line(buf.buf, buf.len))
  			break; /* done with one message */
  	}
  	fclose(output);
  	return status;
  
   corrupt:
  	if (output)
  		fclose(output);
  	unlink(name);
  	fprintf(stderr, "corrupt mailbox\n");
  	exit(1);
  }
  
  static int populate_maildir_list(struct string_list *list, const char *path)
  {
  	DIR *dir;
  	struct dirent *dent;
  	char name[PATH_MAX];
  	char *subs[] = { "cur", "new", NULL };
  	char **sub;
  
  	for (sub = subs; *sub; ++sub) {
  		snprintf(name, sizeof(name), "%s/%s", path, *sub);
  		if ((dir = opendir(name)) == NULL) {
  			if (errno == ENOENT)
  				continue;
  			error("cannot opendir %s (%s)", name, strerror(errno));
  			return -1;
  		}
  
  		while ((dent = readdir(dir)) != NULL) {
  			if (dent->d_name[0] == '.')
  				continue;
  			snprintf(name, sizeof(name), "%s/%s", *sub, dent->d_name);
  			string_list_insert(list, name);
  		}
  
  		closedir(dir);
  	}
  
  	return 0;
  }
  
  static int maildir_filename_cmp(const char *a, const char *b)
  {
  	while (*a && *b) {
  		if (isdigit(*a) && isdigit(*b)) {
  			long int na, nb;
  			na = strtol(a, (char **)&a, 10);
  			nb = strtol(b, (char **)&b, 10);
  			if (na != nb)
  				return na - nb;
  			/* strtol advanced our pointers */
  		}
  		else {
  			if (*a != *b)
  				return (unsigned char)*a - (unsigned char)*b;
  			a++;
  			b++;
  		}
  	}
  	return (unsigned char)*a - (unsigned char)*b;
  }
  
  static int split_maildir(const char *maildir, const char *dir,
  	int nr_prec, int skip)
  {
  	char file[PATH_MAX];
  	char name[PATH_MAX];
  	int ret = -1;
  	int i;
  	struct string_list list = STRING_LIST_INIT_DUP;
  
  	list.cmp = maildir_filename_cmp;
  
  	if (populate_maildir_list(&list, maildir) < 0)
  		goto out;
  
  	for (i = 0; i < list.nr; i++) {
  		FILE *f;
  		snprintf(file, sizeof(file), "%s/%s", maildir, list.items[i].string);
  		f = fopen(file, "r");
  		if (!f) {
  			error("cannot open mail %s (%s)", file, strerror(errno));
  			goto out;
  		}
  
  		if (strbuf_getwholeline(&buf, f, '\n')) {
  			error("cannot read mail %s (%s)", file, strerror(errno));
  			goto out;
  		}
  
  		sprintf(name, "%s/%0*d", dir, nr_prec, ++skip);
  		split_one(f, name, 1);
  
  		fclose(f);
  	}
  
  	ret = skip;
  out:
  	string_list_clear(&list, 1);
  	return ret;
  }
  
  static int split_mbox(const char *file, const char *dir, int allow_bare,
  		      int nr_prec, int skip)
  {
  	char name[PATH_MAX];
  	int ret = -1;
  	int peek;
  
  	FILE *f = !strcmp(file, "-") ? stdin : fopen(file, "r");
  	int file_done = 0;
  
  	if (!f) {
  		error("cannot open mbox %s", file);
  		goto out;
  	}
  
  	do {
  		peek = fgetc(f);
  	} while (isspace(peek));
  	ungetc(peek, f);
  
  	if (strbuf_getwholeline(&buf, f, '\n')) {
  		/* empty stdin is OK */
  		if (f != stdin) {
  			error("cannot read mbox %s", file);
  			goto out;
  		}
  		file_done = 1;
  	}
  
  	while (!file_done) {
  		sprintf(name, "%s/%0*d", dir, nr_prec, ++skip);
  		file_done = split_one(f, name, allow_bare);
  	}
  
  	if (f != stdin)
  		fclose(f);
  
  	ret = skip;
  out:
  	return ret;
  }
  
  int cmd_mailsplit(int argc, const char **argv, const char *prefix)
  {
  	int nr = 0, nr_prec = 4, num = 0;
  	int allow_bare = 0;
  	const char *dir = NULL;
  	const char **argp;
  	static const char *stdin_only[] = { "-", NULL };
  
  	for (argp = argv+1; *argp; argp++) {
  		const char *arg = *argp;
  
  		if (arg[0] != '-')
  			break;
  		/* do flags here */
  		if ( arg[1] == 'd' ) {
  			nr_prec = strtol(arg+2, NULL, 10);
  			if (nr_prec < 3 || 10 <= nr_prec)
  				usage(git_mailsplit_usage);
  			continue;
  		} else if ( arg[1] == 'f' ) {
  			nr = strtol(arg+2, NULL, 10);
  		} else if ( arg[1] == 'h' ) {
  			usage(git_mailsplit_usage);
  		} else if ( arg[1] == 'b' && !arg[2] ) {
  			allow_bare = 1;
  		} else if (!strcmp(arg, "--keep-cr")) {
  			keep_cr = 1;
  		} else if ( arg[1] == 'o' && arg[2] ) {
  			dir = arg+2;
  		} else if ( arg[1] == '-' && !arg[2] ) {
  			argp++;	/* -- marks end of options */
  			break;
  		} else {
  			die("unknown option: %s", arg);
  		}
  	}
  
  	if ( !dir ) {
  		/* Backwards compatibility: if no -o specified, accept
  		   <mbox> <dir> or just <dir> */
  		switch (argc - (argp-argv)) {
  		case 1:
  			dir = argp[0];
  			argp = stdin_only;
  			break;
  		case 2:
  			stdin_only[0] = argp[0];
  			dir = argp[1];
  			argp = stdin_only;
  			break;
  		default:
  			usage(git_mailsplit_usage);
  		}
  	} else {
  		/* New usage: if no more argument, parse stdin */
  		if ( !*argp )
  			argp = stdin_only;
  	}
  
  	while (*argp) {
  		const char *arg = *argp++;
  		struct stat argstat;
  		int ret = 0;
  
  		if (arg[0] == '-' && arg[1] == 0) {
  			ret = split_mbox(arg, dir, allow_bare, nr_prec, nr);
  			if (ret < 0) {
  				error("cannot split patches from stdin");
  				return 1;
  			}
  			num += (ret - nr);
  			nr = ret;
  			continue;
  		}
  
  		if (stat(arg, &argstat) == -1) {
  			error("cannot stat %s (%s)", arg, strerror(errno));
  			return 1;
  		}
  
  		if (S_ISDIR(argstat.st_mode))
  			ret = split_maildir(arg, dir, nr_prec, nr);
  		else
  			ret = split_mbox(arg, dir, allow_bare, nr_prec, nr);
  
  		if (ret < 0) {
  			error("cannot split patches from %s", arg);
  			return 1;
  		}
  		num += (ret - nr);
  		nr = ret;
  	}
  
  	printf("%d\n", num);
  
  	return 0;
  }
  