+#include "cache.h"
+#include "exec_cmd.h"
+#define MAX_ARGS 32
+
+extern char **environ;
+static const char *builtin_exec_path = GIT_EXEC_PATH;
+static const char *current_exec_path = NULL;
+
+void git_set_exec_path(const char *exec_path)
+{
+ current_exec_path = exec_path;
+}
+
+
+/* Returns the highest-priority, location to look for git programs. */
+const char *git_exec_path()
+{
+ const char *env;
+
+ if (current_exec_path)
+ return current_exec_path;
+
+ env = getenv("GIT_EXEC_PATH");
+ if (env) {
+ return env;
+ }
+
+ return builtin_exec_path;
+}
+
+
+int execv_git_cmd(char **argv)
+{
+ char git_command[PATH_MAX + 1];
+ char *tmp;
+ int len, err, i;
+ const char *paths[] = { current_exec_path,
+ getenv("GIT_EXEC_PATH"),
+ builtin_exec_path };
+
+ for (i = 0; i < sizeof(paths)/sizeof(paths[0]); ++i) {
+ const char *exec_dir = paths[i];
+ if (!exec_dir) continue;
+
+ if (*exec_dir != '/') {
+ if (!getcwd(git_command, sizeof(git_command))) {
+ fprintf(stderr, "git: cannot determine "
+ "current directory\n");
+ exit(1);
+ }
+ len = strlen(git_command);
+
+ /* Trivial cleanup */
+ while (!strncmp(exec_dir, "./", 2)) {
+ exec_dir += 2;
+ while (*exec_dir == '/')
+ exec_dir++;
+ }
+ snprintf(git_command + len, sizeof(git_command) - len,
+ "/%s", exec_dir);
+ } else {
+ strcpy(git_command, exec_dir);
+ }
+
+ len = strlen(git_command);
+ len += snprintf(git_command + len, sizeof(git_command) - len,
+ "/git-%s", argv[0]);
+
+ if (sizeof(git_command) <= len) {
+ fprintf(stderr,
+ "git: command name given is too long.\n");
+ break;
+ }
+
+ /* argv[0] must be the git command, but the argv array
+ * belongs to the caller, and my be reused in
+ * subsequent loop iterations. Save argv[0] and
+ * restore it on error.
+ */
+
+ tmp = argv[0];
+ argv[0] = git_command;
+
+ /* execve() can only ever return if it fails */
+ execve(git_command, argv, environ);
+
+ err = errno;
+
+ argv[0] = tmp;
+ }
+ return -1;
+
+}
+
+
+int execl_git_cmd(char *cmd,...)
+{
+ int argc;
+ char *argv[MAX_ARGS + 1];
+ char *arg;
+ va_list param;
+
+ va_start(param, cmd);
+ argv[0] = cmd;
+ argc = 1;
+ while (argc < MAX_ARGS) {
+ arg = argv[argc++] = va_arg(param, char *);
+ if (!arg)
+ break;
+ }
+ va_end(param);
+ if (MAX_ARGS <= argc)
+ return error("too many args to run %s", cmd);
+
+ argv[argc] = NULL;
+ return execv_git_cmd(argv);
+}