path: introduce git_fs_path_find_executableethomson/find_executable

Provide a helper function to find an executable in the current process's
PATH.

1 files changed, 56 insertions, 0 deletions

diff --git a/src/fs_path.c b/src/fs_path.c
index 957f389cc..9aa8213dc 100644
--- a/src/fs_path.c
+++ b/src/fs_path.c
@@ -1851,3 +1851,59 @@ cleanup:
 	return ret;
 #endif
 }
+
+int git_fs_path_find_executable(git_str *fullpath, const char *executable)
+{
+#ifdef GIT_WIN32
+	git_win32_path fullpath_w, executable_w;
+	int error;
+
+	if (git__utf8_to_16(executable_w, GIT_WIN_PATH_MAX, executable) < 0)
+		return -1;
+
+	error = git_win32_path_find_executable(fullpath_w, executable_w);
+
+	if (error == 0)
+		error = git_str_put_w(fullpath, fullpath_w, wcslen(fullpath_w));
+
+	return error;
+#else
+	git_str path = GIT_STR_INIT;
+	const char *current_dir, *term;
+	bool found = false;
+
+	if (git__getenv(&path, "PATH") < 0)
+		return -1;
+
+	current_dir = path.ptr;
+
+	while (*current_dir) {
+		if (! (term = strchr(current_dir, GIT_PATH_LIST_SEPARATOR)))
+			term = strchr(current_dir, '\0');
+
+		git_str_clear(fullpath);
+		if (git_str_put(fullpath, current_dir, (term - current_dir)) < 0 ||
+		    git_str_putc(fullpath, '/') < 0 ||
+		    git_str_puts(fullpath, executable) < 0)
+			return -1;
+
+		if (git_fs_path_isfile(fullpath->ptr)) {
+			found = true;
+			break;
+		}
+
+		current_dir = term;
+
+		while (*current_dir == GIT_PATH_LIST_SEPARATOR)
+			current_dir++;
+	}
+
+	git_str_dispose(&path);
+
+	if (found)
+		return 0;
+
+	git_str_clear(fullpath);
+	return GIT_ENOTFOUND;
+#endif
+}