avoid accessing _all_ loose refs in git-show-ref --verify
[git/jrn.git] / builtin-show-ref.c
blob23e0ff8fbfea1ca29e4beb18c95475dd8bdae05b
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "path-list.h"
7 static const char show_ref_usage[] = "git show-ref [-q|--quiet] [--verify] [-h|--head] [-d|--dereference] [-s|--hash[=<length>]] [--abbrev[=<length>]] [--tags] [--heads] [--] [pattern*] | --filter-invalid < ref-list";
9 static int deref_tags = 0, show_head = 0, tags_only = 0, heads_only = 0,
10 found_match = 0, verify = 0, quiet = 0, hash_only = 0, abbrev = 0;
11 static const char **pattern;
13 static int show_ref(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
15 struct object *obj;
16 const char *hex;
17 unsigned char peeled[20];
19 if (tags_only || heads_only) {
20 int match;
22 match = heads_only && !strncmp(refname, "refs/heads/", 11);
23 match |= tags_only && !strncmp(refname, "refs/tags/", 10);
24 if (!match)
25 return 0;
27 if (pattern) {
28 int reflen = strlen(refname);
29 const char **p = pattern, *m;
30 while ((m = *p++) != NULL) {
31 int len = strlen(m);
32 if (len > reflen)
33 continue;
34 if (memcmp(m, refname + reflen - len, len))
35 continue;
36 if (len == reflen)
37 goto match;
38 /* "--verify" requires an exact match */
39 if (verify)
40 continue;
41 if (refname[reflen - len - 1] == '/')
42 goto match;
44 return 0;
47 match:
48 found_match++;
50 /* This changes the semantics slightly that even under quiet we
51 * detect and return error if the repository is corrupt and
52 * ref points at a nonexistent object.
54 if (!has_sha1_file(sha1))
55 die("git-show-ref: bad ref %s (%s)", refname,
56 sha1_to_hex(sha1));
58 if (quiet)
59 return 0;
61 hex = find_unique_abbrev(sha1, abbrev);
62 if (hash_only)
63 printf("%s\n", hex);
64 else
65 printf("%s %s\n", hex, refname);
67 if (!deref_tags)
68 return 0;
70 if ((flag & REF_ISPACKED) && !peel_ref(refname, peeled)) {
71 if (!is_null_sha1(peeled)) {
72 hex = find_unique_abbrev(peeled, abbrev);
73 printf("%s %s^{}\n", hex, refname);
76 else {
77 obj = parse_object(sha1);
78 if (!obj)
79 die("git-show-ref: bad ref %s (%s)", refname,
80 sha1_to_hex(sha1));
81 if (obj->type == OBJ_TAG) {
82 obj = deref_tag(obj, refname, 0);
83 hex = find_unique_abbrev(obj->sha1, abbrev);
84 printf("%s %s^{}\n", hex, refname);
87 return 0;
90 static int add_existing(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
92 struct path_list *list = (struct path_list *)cbdata;
93 path_list_insert(refname, list);
94 return 0;
98 * read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,
99 * and
100 * (1) strip "^{}" at the end of line if any;
101 * (2) ignore if match is provided and does not head-match refname;
102 * (3) warn if refname is not a well-formed refname and skip;
103 * (4) ignore if refname is a ref that exists in the local repository;
104 * (5) otherwise output the line.
106 static int exclude_existing(const char *match)
108 static struct path_list existing_refs = { NULL, 0, 0, 0 };
109 char buf[1024];
110 int matchlen = match ? strlen(match) : 0;
112 for_each_ref(add_existing, &existing_refs);
113 while (fgets(buf, sizeof(buf), stdin)) {
114 int len = strlen(buf);
115 char *ref;
116 if (len > 0 && buf[len - 1] == '\n')
117 buf[--len] = '\0';
118 if (!strcmp(buf + len - 3, "^{}")) {
119 len -= 3;
120 buf[len] = '\0';
122 for (ref = buf + len; buf < ref; ref--)
123 if (isspace(ref[-1]))
124 break;
125 if (match) {
126 int reflen = buf + len - ref;
127 if (reflen < matchlen)
128 continue;
129 if (strncmp(ref, match, matchlen))
130 continue;
132 if (check_ref_format(ref)) {
133 fprintf(stderr, "warning: ref '%s' ignored\n", ref);
134 continue;
136 if (!path_list_has_path(&existing_refs, ref)) {
137 printf("%s\n", buf);
140 return 0;
143 int cmd_show_ref(int argc, const char **argv, const char *prefix)
145 int i;
147 for (i = 1; i < argc; i++) {
148 const char *arg = argv[i];
149 if (*arg != '-') {
150 pattern = argv + i;
151 break;
153 if (!strcmp(arg, "--")) {
154 pattern = argv + i + 1;
155 if (!*pattern)
156 pattern = NULL;
157 break;
159 if (!strcmp(arg, "-q") || !strcmp(arg, "--quiet")) {
160 quiet = 1;
161 continue;
163 if (!strcmp(arg, "-h") || !strcmp(arg, "--head")) {
164 show_head = 1;
165 continue;
167 if (!strcmp(arg, "-d") || !strcmp(arg, "--dereference")) {
168 deref_tags = 1;
169 continue;
171 if (!strcmp(arg, "-s") || !strcmp(arg, "--hash")) {
172 hash_only = 1;
173 continue;
175 if (!strncmp(arg, "--hash=", 7) ||
176 (!strncmp(arg, "--abbrev", 8) &&
177 (arg[8] == '=' || arg[8] == '\0'))) {
178 if (arg[3] != 'h' && !arg[8])
179 /* --abbrev only */
180 abbrev = DEFAULT_ABBREV;
181 else {
182 /* --hash= or --abbrev= */
183 char *end;
184 if (arg[3] == 'h') {
185 hash_only = 1;
186 arg += 7;
188 else
189 arg += 9;
190 abbrev = strtoul(arg, &end, 10);
191 if (*end || abbrev > 40)
192 usage(show_ref_usage);
193 if (abbrev < MINIMUM_ABBREV)
194 abbrev = MINIMUM_ABBREV;
196 continue;
198 if (!strcmp(arg, "--verify")) {
199 verify = 1;
200 continue;
202 if (!strcmp(arg, "--tags")) {
203 tags_only = 1;
204 continue;
206 if (!strcmp(arg, "--heads")) {
207 heads_only = 1;
208 continue;
210 if (!strcmp(arg, "--exclude-existing"))
211 return exclude_existing(NULL);
212 if (!strncmp(arg, "--exclude-existing=", 19))
213 return exclude_existing(arg + 19);
214 usage(show_ref_usage);
217 if (verify) {
218 unsigned char sha1[20];
220 while (*pattern) {
221 if (resolve_ref(*pattern, sha1, 1, NULL))
222 printf("%s %s\n", sha1_to_hex(sha1),
223 *pattern);
224 else if (!quiet)
225 die("'%s' - not a valid ref", *pattern);
226 else
227 return 1;
228 pattern++;
230 return 0;
233 if (show_head)
234 head_ref(show_ref, NULL);
235 for_each_ref(show_ref, NULL);
236 if (!found_match) {
237 if (verify && !quiet)
238 die("No match");
239 return 1;
241 return 0;