Re: [netcf-devel] [PATCH 2/2] Capture stdout and stderr when execing external programs

On 05/16/2011 11:47 AM, Laine Stump wrote: > This is in response to: > > https://bugzilla.redhat.com/show_bug.cgi?id=616060 > > but will also be useful in an upcoming patch which needs to retrieve > the output of /etc/rc.d/init.d/netcf-transaction. > > Before forking, we now create a pipe, then after forking, the child > dup2's both stdout and stderr to the write side of the pipe, and the > parent calls fdopen() on the read side of the pipe and then calls > gnulib's fread_file() before calling waitpid() to reap the process. > --- > src/dutil_linux.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++---- > src/dutil_linux.h | 2 +- > 2 files changed, 75 insertions(+), 7 deletions(-) > > @@ -133,6 +153,18 @@ exec_program(struct netcf *ncf, > _exit(126); > } > > + if (pipeout[1]>= 0) { > + /* direct stdout and stderr to the pipe */ > + if (dup2(pipeout[1], fileno(stdout))< 0 > + || dup2(pipeout[1], fileno(stderr))< 0) { > + /* return a unique code and let the parent log the error */ > + _exit(125); > + ERR_THROW(WEXITSTATUS(exitstatus) == 125, ncf, EEXEC, > + "Running '%s' failed to dup2 child process stdout/stderr", > + argv_str); Again, a symbolic name instead of hard-coded 125 would be nicer. ACK with that change.