Merge branch 'jc/add'
[git.git] / exec_cmd.c
1 #include "cache.h"
2 #include "exec_cmd.h"
3 #define MAX_ARGS        32
4
5 extern char **environ;
6 static const char *builtin_exec_path = GIT_EXEC_PATH;
7 static const char *current_exec_path = NULL;
8
9 void git_set_exec_path(const char *exec_path)
10 {
11         current_exec_path = exec_path;
12 }
13
14
15 /* Returns the highest-priority, location to look for git programs. */
16 const char *git_exec_path()
17 {
18         const char *env;
19
20         if (current_exec_path)
21                 return current_exec_path;
22
23         env = getenv("GIT_EXEC_PATH");
24         if (env) {
25                 return env;
26         }
27
28         return builtin_exec_path;
29 }
30
31
32 int execv_git_cmd(char **argv)
33 {
34         char git_command[PATH_MAX + 1];
35         char *tmp;
36         int len, err, i;
37         const char *paths[] = { current_exec_path,
38                                 getenv("GIT_EXEC_PATH"),
39                                 builtin_exec_path };
40
41         for (i = 0; i < sizeof(paths)/sizeof(paths[0]); ++i) {
42                 const char *exec_dir = paths[i];
43                 if (!exec_dir) continue;
44
45                 if (*exec_dir != '/') {
46                         if (!getcwd(git_command, sizeof(git_command))) {
47                                 fprintf(stderr, "git: cannot determine "
48                                         "current directory\n");
49                                 exit(1);
50                         }
51                         len = strlen(git_command);
52
53                         /* Trivial cleanup */
54                         while (!strncmp(exec_dir, "./", 2)) {
55                                 exec_dir += 2;
56                                 while (*exec_dir == '/')
57                                         exec_dir++;
58                         }
59                         snprintf(git_command + len, sizeof(git_command) - len,
60                                  "/%s", exec_dir);
61                 } else {
62                         strcpy(git_command, exec_dir);
63                 }
64
65                 len = strlen(git_command);
66                 len += snprintf(git_command + len, sizeof(git_command) - len,
67                                 "/git-%s", argv[0]);
68
69                 if (sizeof(git_command) <= len) {
70                         fprintf(stderr,
71                                 "git: command name given is too long.\n");
72                         break;
73                 }
74
75                 /* argv[0] must be the git command, but the argv array
76                  * belongs to the caller, and my be reused in
77                  * subsequent loop iterations. Save argv[0] and
78                  * restore it on error.
79                  */
80
81                 tmp = argv[0];
82                 argv[0] = git_command;
83
84                 /* execve() can only ever return if it fails */
85                 execve(git_command, argv, environ);
86
87                 err = errno;
88
89                 argv[0] = tmp;
90         }
91         return -1;
92
93 }
94
95
96 int execl_git_cmd(char *cmd,...)
97 {
98         int argc;
99         char *argv[MAX_ARGS + 1];
100         char *arg;
101         va_list param;
102
103         va_start(param, cmd);
104         argv[0] = cmd;
105         argc = 1;
106         while (argc < MAX_ARGS) {
107                 arg = argv[argc++] = va_arg(param, char *);
108                 if (!arg)
109                         break;
110         }
111         va_end(param);
112         if (MAX_ARGS <= argc)
113                 return error("too many args to run %s", cmd);
114
115         argv[argc] = NULL;
116         return execv_git_cmd(argv);
117 }