Function file_callback

builtin/grep.c:955–989

}

static int file_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	int from_stdin;
	const char *filename = arg;
	FILE *patterns;
	int lno = 0;
	struct strbuf sb = STRBUF_INIT;

	BUG_ON_OPT_NEG(unset);

	if (!*filename)
		; /* leave it as-is */
	else
		filename = prefix_filename_except_for_dash(grep_prefix, filename);

	from_stdin = !strcmp(filename, "-");
	patterns = from_stdin ? stdin : fopen(filename, "r");
	if (!patterns)
		die_errno(_("cannot open '%s'"), arg);
	while (strbuf_getline(&sb, patterns) == 0) {
		/* ignore empty line like grep does */
		if (sb.len == 0)
			continue;

		append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
				GREP_PATTERN);
	}
	if (!from_stdin)
		fclose(patterns);
	strbuf_release(&sb);
	if (filename != arg)
		free((void *)filename);
	return 0;
}

static int not_callback(const struct option *opt, const char *arg, int unset)
{