On Friday 08 May 2009 16:59:19 Etaoin Shrdlu wrote: > On Friday 8 May 2009, 16:10, Alan McKinnon wrote: > > On Friday 08 May 2009 16:01:14 Mike Kazantsev wrote: > > > On Fri, 8 May 2009 14:38:58 +0100 > > > > > > Stroller <strol...@stellar.eclipse.co.uk> wrote: > > > > To find the part to which I refer you'll need to scroll down about > > > > halfway through that page to "Colorize grep"; the author advises > > > > adding: > > > > > > > > if echo hello|grep --color=auto l >/dev/null 2>&1; then > > > > export GREP_OPTIONS='--color=auto' GREP_COLOR='1;32' > > > > fi > > > > > > > > to ~/.bashrc > > > > > > > > Why does he echo hello, please? > > > > > > Some greps (like BSD one) might not support '--color' option, so > > > "echo hello|grep --color=auto l" will return error code, skipping if > > > clause, and won't break grep operation by adding an unsupported > > > option. > > > > except that STDERR is combined with STDOUT and sent to /dev/null so > > the script will never get it, the if is always true and the entire > > check is redundant. Better would be > > > > if echo hello|grep --color=auto l >/dev/null ; then > > That will output an uncaptured error message if --color is not supported.
which is the desired effect. It causes the if to be false and the grep options are not enabled (as they are not supported) -- alan dot mckinnon at gmail dot com
