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What shells fail to work if comparing with "" ?
From: |
Dr. David Kirkby |
Subject: |
What shells fail to work if comparing with "" ? |
Date: |
Thu, 10 Feb 2011 18:56:24 +0000 |
User-agent: |
Mozilla/5.0 (X11; U; SunOS i86pc; en-US; rv:1.9.1.7) Gecko/20100214 Thunderbird/3.0.1 |
I know its considered bad practice to check for an empty string with something
like:
if [ "$STR" = "" ] ; then
but what shells do actually break with this, and under what conditions?
I was proposing someone change a test like that to
if [ "x$STR" = ] ; then
but someone has argued against this, saying he knows of no shell where the
former is not acceptable. I realise this issue is probably more of a problem
with older shells, but can anyone give me any examples of where the former will
break, but the latter will be ok?
--
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Dave
- What shells fail to work if comparing with "" ?,
Dr. David Kirkby <=