Merge branch 'maint'
[git] / exec_cmd.c
1 #include "cache.h"
2 #include "exec_cmd.h"
3 #include "quote.h"
4 #define MAX_ARGS        32
5
6 extern char **environ;
7 static const char *builtin_exec_path = GIT_EXEC_PATH;
8 static const char *current_exec_path;
9
10 void git_set_exec_path(const char *exec_path)
11 {
12         current_exec_path = exec_path;
13 }
14
15
16 /* Returns the highest-priority, location to look for git programs. */
17 const char *git_exec_path(void)
18 {
19         const char *env;
20
21         if (current_exec_path)
22                 return current_exec_path;
23
24         env = getenv(EXEC_PATH_ENVIRONMENT);
25         if (env && *env) {
26                 return env;
27         }
28
29         return builtin_exec_path;
30 }
31
32
33 int execv_git_cmd(const char **argv)
34 {
35         char git_command[PATH_MAX + 1];
36         int i;
37         const char *paths[] = { current_exec_path,
38                                 getenv(EXEC_PATH_ENVIRONMENT),
39                                 builtin_exec_path };
40
41         for (i = 0; i < ARRAY_SIZE(paths); ++i) {
42                 size_t len;
43                 int rc;
44                 const char *exec_dir = paths[i];
45                 const char *tmp;
46
47                 if (!exec_dir || !*exec_dir) continue;
48
49                 if (*exec_dir != '/') {
50                         if (!getcwd(git_command, sizeof(git_command))) {
51                                 fprintf(stderr, "git: cannot determine "
52                                         "current directory: %s\n",
53                                         strerror(errno));
54                                 break;
55                         }
56                         len = strlen(git_command);
57
58                         /* Trivial cleanup */
59                         while (!prefixcmp(exec_dir, "./")) {
60                                 exec_dir += 2;
61                                 while (*exec_dir == '/')
62                                         exec_dir++;
63                         }
64
65                         rc = snprintf(git_command + len,
66                                       sizeof(git_command) - len, "/%s",
67                                       exec_dir);
68                         if (rc < 0 || rc >= sizeof(git_command) - len) {
69                                 fprintf(stderr, "git: command name given "
70                                         "is too long.\n");
71                                 break;
72                         }
73                 } else {
74                         if (strlen(exec_dir) + 1 > sizeof(git_command)) {
75                                 fprintf(stderr, "git: command name given "
76                                         "is too long.\n");
77                                 break;
78                         }
79                         strcpy(git_command, exec_dir);
80                 }
81
82                 len = strlen(git_command);
83                 rc = snprintf(git_command + len, sizeof(git_command) - len,
84                               "/git-%s", argv[0]);
85                 if (rc < 0 || rc >= sizeof(git_command) - len) {
86                         fprintf(stderr,
87                                 "git: command name given is too long.\n");
88                         break;
89                 }
90
91                 /* argv[0] must be the git command, but the argv array
92                  * belongs to the caller, and my be reused in
93                  * subsequent loop iterations. Save argv[0] and
94                  * restore it on error.
95                  */
96
97                 tmp = argv[0];
98                 argv[0] = git_command;
99
100                 trace_argv_printf(argv, -1, "trace: exec:");
101
102                 /* execve() can only ever return if it fails */
103                 execve(git_command, (char **)argv, environ);
104
105                 trace_printf("trace: exec failed: %s\n", strerror(errno));
106
107                 argv[0] = tmp;
108         }
109         return -1;
110
111 }
112
113
114 int execl_git_cmd(const char *cmd,...)
115 {
116         int argc;
117         const char *argv[MAX_ARGS + 1];
118         const char *arg;
119         va_list param;
120
121         va_start(param, cmd);
122         argv[0] = cmd;
123         argc = 1;
124         while (argc < MAX_ARGS) {
125                 arg = argv[argc++] = va_arg(param, char *);
126                 if (!arg)
127                         break;
128         }
129         va_end(param);
130         if (MAX_ARGS <= argc)
131                 return error("too many args to run %s", cmd);
132
133         argv[argc] = NULL;
134         return execv_git_cmd(argv);
135 }