On Fri, 16 Nov 2007 22:01:34 +0100, Stefan Fritsch wrote: [...] > The fix is to use "${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}" instead of > ":$LD_LIBRARY_PATH". This will get rid of the colon if LD_LIBRARY_PATH > is unset. (Actually, some scripts use "${LD_LIBRARY_PATH+: > $LD_LIBRARY_PATH}", which seems to work, too. But this is not > documented in the bash man page, at least I can't find it.)
Actually it is documented, just above the description of the various expansions: bash tests for a parameter that is unset or null; omitting the colon results in a test only for a parameter that is unset. Given that a null LD_LIBRARY_PATH seems to have no effect, just as if it were unset, the :+ form appears to be more appropriate. -- MichaĆ Politowski Talking has been known to lead to communication if practiced carelessly.
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