Bash behaving differently
 

Hello,

This is strange and I have no clue why:

On my desktop system (opensuse 11) the following script runs without an issue on bash 3.2.39

echo " " >> $ilog
echo "==> Copying $apps directory " >> $ilog
let "ix=0"
while [ "$ix" -lt 5 ]
do
rsync $opt $apps $rserver$m_bkps 1>> $ilog 2>> $elog
rc=$?
if [[ $rc -gt 0 ]]; then
let "ix+=1"
else
let "ix=5"
fi
done
if [[ $rc -gt 0 ]]; then
echo " " >> $elog
echo ">>> Error copying dir: $apps. rc=$rc <<<" >> $elog
exit 1
fi

On my server (ubuntu 8.04) the same script fails. Bash 3.2.39

It complains about "let" and "[[".
I had to change it to this:
date >> $ilog
echo " " >> $ilog
echo "==> Copying $srcdir directory " >> $ilog
ix=0
while [ $ix -lt 3 ]
do
rsync $opt * $trgdir 1>> $ilog 2>> $elog
rc=$?
if [[ $rc -gt 0 ]]; then
ix=$(($ix+1))
else
ix=3
fi
done
if [ $rc -gt 0 ]; then
echo " " >> $elog
echo ">>> copy dir failed: $srcdir. rc=$rc <<<" >>$elog
exit 1
fi

I had to change let to use $(()) and [[ to [

WHY ?

I bet your script has "#!/bin/sh" at the top. On the ubuntu system change it to "#!/bin/bash".
Ubuntu 8.04 and some earlier versions link /bin/sh to dash rather than bash, though bash is used for login and interactive shells. The ubuntu developers say that dash executes faster than bash and saves some time at bootup.

I ran into similar problems when I upgraded from ubuntu 6.06, which still used bash for everything, to 8.04, and it had me really confused for a while too.

That's exactly right. I would have spent hours trying to figure this one out, and end up frustrated.

Thanks for the info and for averting countless hours of frustration.