[PATCH 1/2] perf script: Show proper message when failed list scripts

[He Kuang <hekuang@huawei.com>]

Perf shows the usage message when perf scripts folder failed to open,
which misleads users to let them think the command is mistyped. This
patch shows proper message and guide the users to check PERF_EXEC_PATH
environment in that case.

Before:
  $ perf script --list

  Usage: perf script [<options>]
   or: perf script [<options>] record <script> [<record-options>] <command>
   or: perf script [<options>] report <script> [script-args]
   or: perf script [<options>] <script> [<record-options>] <command>
   or: perf script [<options>] <top-script> [script-args]

      -l, --list            list available scripts

After:
  $ perf script --list
  open(/home/user/perf-core/scripts) failed.
  Check for "PERF_EXEC_PATH" env to set scripts dir.

Signed-off-by: He Kuang <hekuang@huawei.com>
---
 tools/perf/builtin-script.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 971ff91..d47aef9 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1690,8 +1690,13 @@ static int list_available_scripts(const struct option *opt __maybe_unused,
 	snprintf(scripts_path, MAXPATHLEN, "%s/scripts", get_argv_exec_path());
 
 	scripts_dir = opendir(scripts_path);
-	if (!scripts_dir)
-		return -1;
+	if (!scripts_dir) {
+		fprintf(stdout,
+			"open(%s) failed.\n"
+			"Check \"PERF_EXEC_PATH\" env to set scripts dir.\n",
+			scripts_path);
+		exit(-1);
+	}
 
 	for_each_lang(scripts_path, scripts_dir, lang_dirent) {
 		snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path,
-- 
1.8.5.2