remove unnecessary initializations
[git/git.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("GIT_EXEC_PATH");
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("GIT_EXEC_PATH"),
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 (!strncmp(exec_dir, "./", 2)) {
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 if (getenv("GIT_TRACE")) {
101 const char **p = argv;
102 fputs("trace: exec:", stderr);
103 while (*p) {
104 fputc(' ', stderr);
105 sq_quote_print(stderr, *p);
106 ++p;
107 }
108 putc('\n', stderr);
109 fflush(stderr);
110 }
111
112 /* execve() can only ever return if it fails */
113 execve(git_command, (char **)argv, environ);
114
115 if (getenv("GIT_TRACE")) {
116 fprintf(stderr, "trace: exec failed: %s\n",
117 strerror(errno));
118 fflush(stderr);
119 }
120
121 argv[0] = tmp;
122 }
123 return -1;
124
125 }
126
127
128 int execl_git_cmd(const char *cmd,...)
129 {
130 int argc;
131 const char *argv[MAX_ARGS + 1];
132 const char *arg;
133 va_list param;
134
135 va_start(param, cmd);
136 argv[0] = cmd;
137 argc = 1;
138 while (argc < MAX_ARGS) {
139 arg = argv[argc++] = va_arg(param, char *);
140 if (!arg)
141 break;
142 }
143 va_end(param);
144 if (MAX_ARGS <= argc)
145 return error("too many args to run %s", cmd);
146
147 argv[argc] = NULL;
148 return execv_git_cmd(argv);
149 }