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authorMichal Ostrowski <mostrows@watson.ibm.com>2006-01-11 02:12:17 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-01-14 00:49:01 (GMT)
commit77cb17e940c806a4cc811bfd66187277b729a1e7 (patch)
treeaae0b04758379c89b2dd2d02dd44c97b4d33998f /exec_cmd.c
parentc884dd9a54fcde71ea125c86e6b6ab92acbbc7cf (diff)
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Exec git programs without using PATH.
The git suite may not be in PATH (and thus programs such as git-send-pack could not exec git-rev-list). Thus there is a need for logic that will locate these programs. Modifying PATH is not desirable as it result in behavior differing from the user's intentions, as we may end up prepending "/usr/bin" to PATH. - git C programs will use exec*_git_cmd() APIs to exec sub-commands. - exec*_git_cmd() will execute a git program by searching for it in the following directories: 1. --exec-path (as used by "git") 2. The GIT_EXEC_PATH environment variable. 3. $(gitexecdir) as set in Makefile (default value $(bindir)). - git wrapper will modify PATH as before to enable shell scripts to invoke "git-foo" commands. Ideally, shell scripts should use the git wrapper to become independent of PATH, and then modifying PATH will not be necessary. [jc: with minor updates after a brief review.] Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'exec_cmd.c')
-rw-r--r--exec_cmd.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/exec_cmd.c b/exec_cmd.c
new file mode 100644
index 0000000..55af33b
--- /dev/null
+++ b/exec_cmd.c
@@ -0,0 +1,117 @@
+#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);
+}