wipjc/is-git-command

3 files changed, 70 insertions, 6 deletions

diff --git a/builtin/help.c b/builtin/help.c
index cc17e670ce..a31a538cbd 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -286,12 +286,6 @@ static int git_help_config(const char *var, const char *value, void *cb)
 
 static struct cmdnames main_cmds, other_cmds;
 
-static int is_git_command(const char *s)
-{
-	return is_in_cmdlist(&main_cmds, s) ||
-		is_in_cmdlist(&other_cmds, s);
-}
-
 static const char *prepend(const char *prefix, const char *cmd)
 {
 	size_t pre_len = strlen(prefix);
diff --git a/help.c b/help.c
index df7d16d7ce..714a998fd6 100644
--- a/help.c
+++ b/help.c
@@ -166,6 +166,75 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 	strbuf_release(&buf);
 }
 
+static int command_exists_in_dir(const char *path, const char *name)
+{
+	int ret;
+	struct strbuf buf = STRBUF_INIT;
+
+	strbuf_addf(&buf, "%s/%s", path, name);
+	ret = is_executable(buf.buf);
+	strbuf_release(&buf);
+	return ret;
+}
+
+static void add_name_to_path(struct strbuf *buf,
+			     const char *path,
+			     int pathlen, const char *name)
+{
+	if (pathlen < 0)
+		pathlen = strlen(path);
+
+	if (pathlen)
+		strbuf_addf(&buf, "%.*s/%s", pathlen, path, name);
+	else
+		strbuf_addstr(&buf, name);
+
+#if defined(GIT_WINDOWS_NATIVE)
+	strbuf_addstr(&buf, ".exe");
+#endif
+}
+
+int is_git_command(const char *name)
+{
+	struct strbuf buf = STRBUF_INIT;
+	const char *env_path, *exec_path;
+
+	if (is_builtin_command(name))
+		return 1;
+
+	exec_path = git_exec_path();
+	if (exec_path) {
+		add_name_to_path(&buf, exec_path, -1, name);
+		if (is_executable(buf.buf))
+			goto found;
+		strbuf_reset(&buf);
+	}
+
+	env_path = getenv("PATH");
+	if (env_path) {
+		const char *current = env_path;
+
+		while (1) {
+			const char *next = strchr(current, PATH_SEP);
+
+			add_name_to_path(&buf, current, next - current, name);
+			if (is_executable(buf.buf))
+				goto found;
+			next++;
+			if (!*next)
+				break;
+			current = next;
+		}
+	}
+
+	strbuf_release(&buf);
+	return 0;
+
+found:
+	strbuf_release(&buf);
+	return 1;
+}
+
 void load_command_list(const char *prefix,
 		struct cmdnames *main_cmds,
 		struct cmdnames *other_cmds)
diff --git a/help.h b/help.h
index b21d7c94e8..33b1bfcfb0 100644
--- a/help.h
+++ b/help.h
@@ -24,6 +24,7 @@ extern void load_command_list(const char *prefix,
 extern void add_cmdname(struct cmdnames *cmds, const char *name, int len);
 /* Here we require that excludes is a sorted list. */
 extern void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes);
+extern int is_git_command(const char *name);
 extern int is_in_cmdlist(struct cmdnames *cmds, const char *name);
 extern void list_commands(unsigned int colopts, struct cmdnames *main_cmds, struct cmdnames *other_cmds);