2021-10-30 22:01:51 +0700, Robert Elz via austin-group-l at The Open Group: > Date: Fri, 29 Oct 2021 18:13:29 -0700 > From: Alan Coopersmith <alan.coopersm...@oracle.com> > Message-ID: <e7c56ee8-2103-63d8-07f4-19a0bd359...@oracle.com> > > | The SVR4 implementation (inherited by Solaris & illumos) writes white > | space before each pid to stdout: > > Thanks, with that, and Geoff's reference to XBD 5 to justify it, this > doesn't look quite so useless. > > I still believe we'd probably be better off deleting it, than fixing > the spec though. [...]
While I agree it's badly designed, it's still useful. And since lsof is rarely available, that's generally your only option for this kind of things. Note that its output is non-text (doesn't end in newline and could be larger than LINE_MAX), which means that with the POSIX API, you can't post-process it with text utilities. fuser /some/file 2> /dev/null | xargs kill is not guaranteed to work (not to mention it will call kill without arguments if there's no matching pid). So, one would need something like: (fuser /some/file 2> /dev/null; echo) | fold -b | xargs sh -c ' [ "$#" -ne 0 ] && kill "$@"' sh If one really wanted to use xargs. Or: unset -v IFS set -- $(LC_ALL=POSIX fuser /some/file 2> /dev/null) [ "$#" -ne 0 ] && kill "$@" (using LC_ALL=POSIX because otherwise fuser may surround %d with blanks other than the ones in $IFS by a strict reading of the spec). On most systems, you can do: fuser /some/file 2> /dev/null | xargs -r kill (the -r being implicit in some xargs implementations, making them non-compliant but more sensible). fuser's stderr output is also hardly post-processable reliably. -- Stephane
