tutorial: setting up a tree for subsystem maintainers
[git] / rev-parse.c
1 /*
2  * rev-parse.c
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "cache.h"
7 #include "commit.h"
8 #include "refs.h"
9 #include "quote.h"
10
11 #define DO_REVS         1
12 #define DO_NOREV        2
13 #define DO_FLAGS        4
14 #define DO_NONFLAGS     8
15 static int filter = ~0;
16
17 static char *def = NULL;
18
19 #define NORMAL 0
20 #define REVERSED 1
21 static int show_type = NORMAL;
22 static int symbolic = 0;
23 static int output_sq = 0;
24
25 static int revs_count = 0;
26
27 /*
28  * Some arguments are relevant "revision" arguments,
29  * others are about output format or other details.
30  * This sorts it all out.
31  */
32 static int is_rev_argument(const char *arg)
33 {
34         static const char *rev_args[] = {
35                 "--all",
36                 "--bisect",
37                 "--dense",
38                 "--header",
39                 "--max-age=",
40                 "--max-count=",
41                 "--merge-order",
42                 "--min-age=",
43                 "--no-merges",
44                 "--objects",
45                 "--parents",
46                 "--pretty",
47                 "--show-breaks",
48                 "--sparse",
49                 "--topo-order",
50                 "--unpacked",
51                 NULL
52         };
53         const char **p = rev_args;
54
55         for (;;) {
56                 const char *str = *p++;
57                 int len;
58                 if (!str)
59                         return 0;
60                 len = strlen(str);
61                 if (!strcmp(arg, str) ||
62                     (str[len-1] == '=' && !strncmp(arg, str, len)))
63                         return 1;
64         }
65 }
66
67 /* Output argument as a string, either SQ or normal */
68 static void show(const char *arg)
69 {
70         if (output_sq) {
71                 int sq = '\'', ch;
72
73                 putchar(sq);
74                 while ((ch = *arg++)) {
75                         if (ch == sq)
76                                 fputs("'\\'", stdout);
77                         putchar(ch);
78                 }
79                 putchar(sq);
80                 putchar(' ');
81         }
82         else
83                 puts(arg);
84 }
85
86 /* Output a revision, only if filter allows it */
87 static void show_rev(int type, const unsigned char *sha1, const char *name)
88 {
89         if (!(filter & DO_REVS))
90                 return;
91         def = NULL;
92         revs_count++;
93
94         if (type != show_type)
95                 putchar('^');
96         if (symbolic && name)
97                 show(name);
98         else
99                 show(sha1_to_hex(sha1));
100 }
101
102 /* Output a flag, only if filter allows it. */
103 static void show_flag(char *arg)
104 {
105         if (!(filter & DO_FLAGS))
106                 return;
107         if (filter & (is_rev_argument(arg) ? DO_REVS : DO_NOREV))
108                 show(arg);
109 }
110
111 static void show_default(void)
112 {
113         char *s = def;
114
115         if (s) {
116                 unsigned char sha1[20];
117
118                 def = NULL;
119                 if (!get_sha1(s, sha1)) {
120                         show_rev(NORMAL, sha1, s);
121                         return;
122                 }
123         }
124 }
125
126 static int show_reference(const char *refname, const unsigned char *sha1)
127 {
128         show_rev(NORMAL, sha1, refname);
129         return 0;
130 }
131
132 static void show_datestring(const char *flag, const char *datestr)
133 {
134         static char buffer[100];
135
136         /* date handling requires both flags and revs */
137         if ((filter & (DO_FLAGS | DO_REVS)) != (DO_FLAGS | DO_REVS))
138                 return;
139         snprintf(buffer, sizeof(buffer), "%s%lu", flag, approxidate(datestr));
140         show(buffer);
141 }
142
143 static void show_file(const char *arg)
144 {
145         show_default();
146         if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV))
147                 show(arg);
148 }
149
150 int main(int argc, char **argv)
151 {
152         int i, as_is = 0, verify = 0;
153         unsigned char sha1[20];
154         const char *prefix = setup_git_directory();
155         
156         for (i = 1; i < argc; i++) {
157                 char *arg = argv[i];
158                 char *dotdot;
159         
160                 if (as_is) {
161                         show_file(arg);
162                         continue;
163                 }
164                 if (*arg == '-') {
165                         if (!strcmp(arg, "--")) {
166                                 as_is = 1;
167                                 /* Pass on the "--" if we show anything but files.. */
168                                 if (filter & (DO_FLAGS | DO_REVS))
169                                         show_file(arg);
170                                 continue;
171                         }
172                         if (!strcmp(arg, "--default")) {
173                                 def = argv[i+1];
174                                 i++;
175                                 continue;
176                         }
177                         if (!strcmp(arg, "--revs-only")) {
178                                 filter &= ~DO_NOREV;
179                                 continue;
180                         }
181                         if (!strcmp(arg, "--no-revs")) {
182                                 filter &= ~DO_REVS;
183                                 continue;
184                         }
185                         if (!strcmp(arg, "--flags")) {
186                                 filter &= ~DO_NONFLAGS;
187                                 continue;
188                         }
189                         if (!strcmp(arg, "--no-flags")) {
190                                 filter &= ~DO_FLAGS;
191                                 continue;
192                         }
193                         if (!strcmp(arg, "--verify")) {
194                                 filter &= ~(DO_FLAGS|DO_NOREV);
195                                 verify = 1;
196                                 continue;
197                         }
198                         if (!strcmp(arg, "--sq")) {
199                                 output_sq = 1;
200                                 continue;
201                         }
202                         if (!strcmp(arg, "--not")) {
203                                 show_type ^= REVERSED;
204                                 continue;
205                         }
206                         if (!strcmp(arg, "--symbolic")) {
207                                 symbolic = 1;
208                                 continue;
209                         }
210                         if (!strcmp(arg, "--all")) {
211                                 for_each_ref(show_reference);
212                                 continue;
213                         }
214                         if (!strcmp(arg, "--show-prefix")) {
215                                 if (prefix)
216                                         puts(prefix);
217                                 continue;
218                         }
219                         if (!strcmp(arg, "--git-dir")) {
220                                 const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
221                                 static char cwd[PATH_MAX];
222                                 if (gitdir) {
223                                         puts(gitdir);
224                                         continue;
225                                 }
226                                 if (!prefix) {
227                                         puts(".git");
228                                         continue;
229                                 }
230                                 if (!getcwd(cwd, PATH_MAX))
231                                         die("unable to get current working directory");
232                                 printf("%s/.git\n", cwd);
233                                 continue;
234                         }
235                         if (!strncmp(arg, "--since=", 8)) {
236                                 show_datestring("--max-age=", arg+8);
237                                 continue;
238                         }
239                         if (!strncmp(arg, "--after=", 8)) {
240                                 show_datestring("--max-age=", arg+8);
241                                 continue;
242                         }
243                         if (!strncmp(arg, "--before=", 9)) {
244                                 show_datestring("--min-age=", arg+9);
245                                 continue;
246                         }
247                         if (!strncmp(arg, "--until=", 8)) {
248                                 show_datestring("--min-age=", arg+8);
249                                 continue;
250                         }
251                         if (verify)
252                                 die("Needed a single revision");
253                         show_flag(arg);
254                         continue;
255                 }
256
257                 /* Not a flag argument */
258                 dotdot = strstr(arg, "..");
259                 if (dotdot) {
260                         unsigned char end[20];
261                         char *n = dotdot+2;
262                         *dotdot = 0;
263                         if (!get_sha1(arg, sha1)) {
264                                 if (!*n)
265                                         n = "HEAD";
266                                 if (!get_sha1(n, end)) {
267                                         show_rev(NORMAL, end, n);
268                                         show_rev(REVERSED, sha1, arg);
269                                         continue;
270                                 }
271                         }
272                         *dotdot = '.';
273                 }
274                 if (!get_sha1(arg, sha1)) {
275                         show_rev(NORMAL, sha1, arg);
276                         continue;
277                 }
278                 if (*arg == '^' && !get_sha1(arg+1, sha1)) {
279                         show_rev(REVERSED, sha1, arg+1);
280                         continue;
281                 }
282                 if (verify)
283                         die("Needed a single revision");
284                 as_is = 1;
285                 show_file(arg);
286         }
287         show_default();
288         if (verify && revs_count != 1)
289                 die("Needed a single revision");
290         return 0;
291 }