[tip:perfcounters/core] perf report: Print more expressive message in case of file open error

tip-bot for Ingo Molnar
2009-06-07T16:01:19Z

Commit-ID: a14832ff977e78d1982cdf78cdabb1f2320d9ac8
Gitweb: http://git.kernel.org/tip/a14832ff977e78d1982cdf78cdabb1f2320d9ac8
Author: Ingo Molnar <mingo@elte.hu>
AuthorDate: Sun, 7 Jun 2009 17:58:23 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 7 Jun 2009 17:58:23 +0200

perf report: Print more expressive message in case of file open error

Before:

$ perf report
failed to open file: No such file or directory

After:

$ perf report
failed to open file: perf.data (try 'perf record' first)

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
tools/perf/builtin-report.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 242e09f..f053a74 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1120,7 +1120,10 @@ static int __cmd_report(void)

input = open(input_name, O_RDONLY);
if (input < 0) {
- perror("failed to open file");
+ fprintf(stderr, " failed to open file: %s", input_name);
+ if (!strcmp(input_name, "perf.data"))
+ fprintf(stderr, " (try 'perf record' first)");
+ fprintf(stderr, "\n");
exit(-1);
}