ash and bash1 shell compatibility issues

[Matthias Andree]

Hi,

some more food for the autoconf 2.57 portable shell programming section,
edit and add. This information is public domain.

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This won't work in ash 0.2:

set -e
[ -d directory ] && rm -f -r directory

The shell will exit if the directory does not exist. Normally, the "set
-e" exit is to be suppressed when the failing command is in a pipe
followed by || or &&.

Use 

if [ -d directory ] ; then rm -f -r directory ; else : ; fi

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It also seems that bash1 does not like

trap "if command1 ; then command2 ; else command3 ; fi" 0

It will barf with "syntax error: unexpected token then".

In my particular case, I was able to rewrite as

if command1 ; then trap "command2" 0 ; else command3 ; fi

But this is not generally possible.

-- 
Matthias Andree