git-tag: update usage string and documentation.
[git.git] / merge-index.c
1 #include <sys/types.h>
2 #include <sys/wait.h>
3
4 #include "cache.h"
5
6 static const char *pgm = NULL;
7 static const char *arguments[8];
8 static int one_shot, quiet;
9 static int err;
10
11 static void run_program(void)
12 {
13         int pid = fork(), status;
14
15         if (pid < 0)
16                 die("unable to fork");
17         if (!pid) {
18                 execlp(pgm, arguments[0],
19                             arguments[1],
20                             arguments[2],
21                             arguments[3],
22                             arguments[4],
23                             arguments[5],
24                             arguments[6],
25                             arguments[7],
26                             NULL);
27                 die("unable to execute '%s'", pgm);
28         }
29         if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status)) {
30                 if (one_shot) {
31                         err++;
32                 } else {
33                         if (!quiet)
34                                 die("merge program failed");
35                         exit(1);
36                 }
37         }
38 }
39
40 static int merge_entry(int pos, const char *path)
41 {
42         int found;
43         
44         if (pos >= active_nr)
45                 die("git-merge-index: %s not in the cache", path);
46         arguments[0] = pgm;
47         arguments[1] = "";
48         arguments[2] = "";
49         arguments[3] = "";
50         arguments[4] = path;
51         arguments[5] = "";
52         arguments[6] = "";
53         arguments[7] = "";
54         found = 0;
55         do {
56                 static char hexbuf[4][60];
57                 static char ownbuf[4][60];
58                 struct cache_entry *ce = active_cache[pos];
59                 int stage = ce_stage(ce);
60
61                 if (strcmp(ce->name, path))
62                         break;
63                 found++;
64                 strcpy(hexbuf[stage], sha1_to_hex(ce->sha1));
65                 sprintf(ownbuf[stage], "%o", ntohl(ce->ce_mode) & (~S_IFMT));
66                 arguments[stage] = hexbuf[stage];
67                 arguments[stage + 4] = ownbuf[stage];
68         } while (++pos < active_nr);
69         if (!found)
70                 die("git-merge-index: %s not in the cache", path);
71         run_program();
72         return found;
73 }
74
75 static void merge_file(const char *path)
76 {
77         int pos = cache_name_pos(path, strlen(path));
78
79         /*
80          * If it already exists in the cache as stage0, it's
81          * already merged and there is nothing to do.
82          */
83         if (pos < 0)
84                 merge_entry(-pos-1, path);
85 }
86
87 static void merge_all(void)
88 {
89         int i;
90         for (i = 0; i < active_nr; i++) {
91                 struct cache_entry *ce = active_cache[i];
92                 if (!ce_stage(ce))
93                         continue;
94                 i += merge_entry(i, ce->name)-1;
95         }
96 }
97
98 int main(int argc, char **argv)
99 {
100         int i, force_file = 0;
101
102         if (argc < 3)
103                 usage("git-merge-index [-o] [-q] <merge-program> (-a | <filename>*)");
104
105         read_cache();
106
107         i = 1;
108         if (!strcmp(argv[i], "-o")) {
109                 one_shot = 1;
110                 i++;
111         }
112         if (!strcmp(argv[i], "-q")) {
113                 quiet = 1;
114                 i++;
115         }
116         pgm = argv[i++];
117         for (; i < argc; i++) {
118                 char *arg = argv[i];
119                 if (!force_file && *arg == '-') {
120                         if (!strcmp(arg, "--")) {
121                                 force_file = 1;
122                                 continue;
123                         }
124                         if (!strcmp(arg, "-a")) {
125                                 merge_all();
126                                 continue;
127                         }
128                         die("git-merge-index: unknown option %s", arg);
129                 }
130                 merge_file(arg);
131         }
132         if (err && !quiet)
133                 die("merge program failed");
134         return err;
135 }