On 19/08/09 09:34, Jim Meyering wrote:
There were a few unchecked syscalls in fish.c
From ba8b8b0684a03b6e6fbb939ed7e1cbf5e1000092 Mon Sep 17 00:00:00 2001 From: Jim Meyering<meyering@redhat.com> Date: Wed, 19 Aug 2009 10:01:07 +0200 Subject: [PATCH libguestfs] guestfish: detect a few more failed syscalls
* fish/fish.c (issue_command): Detect/diagnose more failed syscalls. --- fish/fish.c | 26 +++++++++++++++++++++----- 1 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/fish/fish.c b/fish/fish.c index 830617b..e6cd270 100644 --- a/fish/fish.c +++ b/fish/fish.c @@ -750,8 +750,14 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd) if (pipecmd) { int fd[2];
- fflush (stdout); - pipe (fd); + if (fflush (stdout)); {
Looks like a stray semicolon in there. Also, wouldn't it be better form to test for test for a return value of EOF?
+ perror ("failed to flush standard output"); + return -1; + } + if (pipe (fd)) { + perror ("pipe failed"); + return -1; + }
Again, I'd explicitly test for a return value of -1 for consistency.
pid = fork (); if (pid == -1) { perror ("fork"); @@ -760,7 +766,10 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd)
if (pid == 0) { /* Child process. */ close (fd[1]); - dup2 (fd[0], 0); + if (dup2 (fd[0], 0)< 0) { + perror ("dup2 of stdin failed"); + _exit (1); + }
fd[1] ought to be closed after this call. Not directly relevant to this patch, but '0' is a magic number. Use STDIN_FILENO from unistd.h.
r = system (pipecmd); if (r == -1) { @@ -770,9 +779,16 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd) _exit (WEXITSTATUS (r)); }
- stdout_saved_fd = dup (1); + if ((stdout_saved_fd = dup (1))< 0) { + perror ("failed to dup stdout"); + return -1; + }
'1' is a magic number. Use STDOUT_FILENO from unistd.h.
close (fd[0]); - dup2 (fd[1], 1); + if (dup2 (fd[1], 1)) { + perror ("failed to dup stdout"); + close (stdout_saved_fd); + return -1; + }
Test for return value of -1. '1' is a magic number.
close (fd[1]); }
-- 1.6.4.378.g88f2f
Matt -- Matthew Booth, RHCA, RHCSS Red Hat Engineering, Virtualisation Team M: +44 (0)7977 267231 GPG ID: D33C3490 GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490