When using virCommandRunAsync and saving the pid for later, it
is useful to be able to reap that pid in the same way that it
would have been auto-reaped by virCommand if we had passed
NULL for the pid argument in the first place.
* src/util/command.c (virPidWait, virPidAbort): New functions,
created from...
(virCommandWait, virCommandAbort): ...bodies of these.
(includes): Drop duplicate <stdlib.h>. Ensure that our pid_t
assumptions hold.
(virCommandRunAsync): Improve documentation.
* src/util/command.h (virPidWait, virPidAbort): New prototypes.
* src/libvirt_private.syms: Export them.
* docs/internals/command.html.in: Document them.
Guarantee that outbuf/errbuf are allocated on success, even if to the
empty string. Caller always has to free the result, and empty output
check requires checking if *outbuf=='\0'. Makes the API easier to use
safely. Failure is best effort allocation (some paths, like
out-of-memory, cannot allocate a buffer, but most do), so caller must
free buffer on failure.
* docs/internals/command.html.in: Update documentation.
* src/util/command.c (virCommandSetOutputBuffer)
(virCommandSetErrorBuffer, virCommandProcessIO) Guarantee empty
string on no output.
* tests/commandtest.c (test17): New test.
* docs/internals/command.html.in: Better documentation of buffer
vs. fd considerations.
* src/util/command.c (virCommandRunAsync): Reject raw execution
with string io.
(virCommandRun): Reject execution with user-specified fds not
visiting a regular file.
