On Sunday, Sep 28th 2003 at 14:31 +0100, quoth Manoj Kumar:
=>Is there any reason not to use bash features in init
=>scripts?
=>Consider, for example, this fragment from
=>/etc/sysconfig/network-scripts/ifup-post:
=>
=> DEVICETYPE=`echo $DEVICE | sed "s/[0-9]*$//"`
=> REALDEVICE=`echo $DEVICE | sed 's/:.*//g'`
=> if echo $DEVICE | grep -q ':' ; then
=> ISALIAS=yes
=> else
=> ISALIAS=no
=> fi
=>
=>In bash we can do this much faster with something like
=>this:
=>
=> DEVICETYPE=$DEVICE
=> while [[ $DEVICETYPE == *[0-9] ]]; do
=> DEVICETYPE=${DEVICETYPE%[0-9]}
=> done
=> REALDEVICE=${DEVICE%%:*}
=> if [[ $DEVICE == *:* ]]; then
=> ISALIAS=yes
=> else
=> ISALIAS=no
=> fi
=>
=>Okay, the loop that replaces the first line is messy, but it saves a
=>couple of forks and an exec. The other two changes are both simpler and
=>faster.
=>
=>So why do most init scripts use sed and grep to process strings? It
=>can't be a desire to allow them to work with the Bourne shell (why would
=>we want that anyway?) because some scripts do use bash features.
You have my blessing.
--
-Time flies like the wind. Fruit flies like a banana. Stranger things have -
-happened but none stranger than this. Does your driver's license say Organ
-Donor?Black holes are where God divided by zero. Listen to me! We are all-
-individuals! What if this weren't a hypothetical question?
steveo at syslang.net
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