Documentation/describe: improve one-line summary
[git.git] / exec_cmd.c
blob698e7526c40749fd333367018c192537cf6b4562
1 #include "cache.h"
2 #include "exec_cmd.h"
3 #include "quote.h"
4 #define MAX_ARGS 32
6 static const char *argv_exec_path;
7 static const char *argv0_path;
9 const char *system_path(const char *path)
11 #ifdef RUNTIME_PREFIX
12 static const char *prefix;
13 #else
14 static const char *prefix = PREFIX;
15 #endif
16 struct strbuf d = STRBUF_INIT;
18 if (is_absolute_path(path))
19 return path;
21 #ifdef RUNTIME_PREFIX
22 assert(argv0_path);
23 assert(is_absolute_path(argv0_path));
25 if (!prefix &&
26 !(prefix = strip_path_suffix(argv0_path, GIT_EXEC_PATH)) &&
27 !(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
28 !(prefix = strip_path_suffix(argv0_path, "git"))) {
29 prefix = PREFIX;
30 trace_printf("RUNTIME_PREFIX requested, "
31 "but prefix computation failed. "
32 "Using static fallback '%s'.\n", prefix);
34 #endif
36 strbuf_addf(&d, "%s/%s", prefix, path);
37 path = strbuf_detach(&d, NULL);
38 return path;
41 const char *git_extract_argv0_path(const char *argv0)
43 const char *slash;
45 if (!argv0 || !*argv0)
46 return NULL;
47 slash = argv0 + strlen(argv0);
49 while (argv0 <= slash && !is_dir_sep(*slash))
50 slash--;
52 if (slash >= argv0) {
53 argv0_path = xstrndup(argv0, slash - argv0);
54 return slash + 1;
57 return argv0;
60 void git_set_argv_exec_path(const char *exec_path)
62 argv_exec_path = exec_path;
64 * Propagate this setting to external programs.
66 setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
70 /* Returns the highest-priority, location to look for git programs. */
71 const char *git_exec_path(void)
73 const char *env;
75 if (argv_exec_path)
76 return argv_exec_path;
78 env = getenv(EXEC_PATH_ENVIRONMENT);
79 if (env && *env) {
80 return env;
83 return system_path(GIT_EXEC_PATH);
86 static void add_path(struct strbuf *out, const char *path)
88 if (path && *path) {
89 strbuf_add_absolute_path(out, path);
90 strbuf_addch(out, PATH_SEP);
94 void setup_path(void)
96 const char *old_path = getenv("PATH");
97 struct strbuf new_path = STRBUF_INIT;
99 add_path(&new_path, git_exec_path());
100 add_path(&new_path, argv0_path);
102 if (old_path)
103 strbuf_addstr(&new_path, old_path);
104 else
105 strbuf_addstr(&new_path, _PATH_DEFPATH);
107 setenv("PATH", new_path.buf, 1);
109 strbuf_release(&new_path);
112 const char **prepare_git_cmd(const char **argv)
114 int argc;
115 const char **nargv;
117 for (argc = 0; argv[argc]; argc++)
118 ; /* just counting */
119 nargv = xmalloc(sizeof(*nargv) * (argc + 2));
121 nargv[0] = "git";
122 for (argc = 0; argv[argc]; argc++)
123 nargv[argc + 1] = argv[argc];
124 nargv[argc + 1] = NULL;
125 return nargv;
128 int execv_git_cmd(const char **argv) {
129 const char **nargv = prepare_git_cmd(argv);
130 trace_argv_printf(nargv, "trace: exec:");
132 /* execvp() can only ever return if it fails */
133 sane_execvp("git", (char **)nargv);
135 trace_printf("trace: exec failed: %s\n", strerror(errno));
137 free(nargv);
138 return -1;
142 int execl_git_cmd(const char *cmd,...)
144 int argc;
145 const char *argv[MAX_ARGS + 1];
146 const char *arg;
147 va_list param;
149 va_start(param, cmd);
150 argv[0] = cmd;
151 argc = 1;
152 while (argc < MAX_ARGS) {
153 arg = argv[argc++] = va_arg(param, char *);
154 if (!arg)
155 break;
157 va_end(param);
158 if (MAX_ARGS <= argc)
159 return error("too many args to run %s", cmd);
161 argv[argc] = NULL;
162 return execv_git_cmd(argv);