On Wed, Apr 19, 2023 at 03:53:57PM +0200, Laszlo Ersek wrote: > >> snprintf (cmd, sizeof cmd, > >> - "if %s --object tls-creds-x509,id=tls0 |& grep -sq 'TLS > >> credentials support requires GNUTLS'; then exit 1; else exit 0; fi", > >> + "if %s --object tls-creds-x509,id=tls0 \\\n" > >> + " |& grep -sq 'TLS credentials support requires GNUTLS'\n" > > > > Note: |& is a bashism; but system() might not invoke bash. So this is > > already non-portable code; and we should be fixing that. (I don't > > mind doing it as a followup if you end up pushing before seeing this > > message). > > I noticed |& too; my thought was "TIL". :) > > > > >> + "then\n" > >> + " exit 1\n" > >> + "else\n" > >> + " exit 0\n" > >> + "fi\n", > > > > For that matter, 'if ...; then exit 1; else exit 0; fi' can be > > compressed to '! ...'. > > > > Yes, I noticed that too, but I assumed there was a finer point I was > missing. :/
autoconf still avoids it because of portability to Solaris /bin/sh (not /bin/xpg4/sh), which lacked !. But that's ancient history these days; ALL modern sh support ! correctly. (Note that support for '! command...' is different than 'test ! expr...', which itself has its own set of portability pitfalls that autoconf cares about; but that is yet another place where modern sh is now quite portable). -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
