Bash arrays and case statements - review my script
- by Felipe Alvarez
#!/bin/bash
# Change the environment in which you are currently working.
# Actually, it calls the relevant 'lettus.sh' script
if [ "${BASH_SOURCE[0]}" == "$0" ]; then
echo "Try running this as \". chenv $1\""
exit 0
fi
usage(){
echo "Usage: . ${PROG} -- Shows a list of user-selectable environments."
echo " . ${PROG} [env] -- Select environment."
echo " . ${PROG} -h -- Shows this usage screen."
return
}
showEnv(){
# check if index0 exists, assume we have at least the first (zeroth) element
#if [ -z "${envList}" ]; then
if [ -z "${envList[0]}" ]; then
echo "array \$envList is empty! " >&2
return 1
fi
# Show all elements in array (0 -> n-1)
for i in $(seq 0 $((${#envList[@]} - 1))); do
echo ${envList[$i]}
done
return
}
setEnv(){
if [ -z "$1" ]; then
usage; return
fi
case $1 in
cold) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_cold.sh;;
coles) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_coles.sh;;
fc) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_fc.sh;;
fcrm) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_fcrm.sh;;
stable) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_stable.sh;;
tip) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_tip.sh;;
uat) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_uat.sh;;
wellmdc) FILE_TO_SOURCE=/u2/tip/conf/ctrl/lettus_wellmdc.sh;;
*) usage; return;;
esac
if $IS_SOURCED; then
echo "Environment \"$1\" selected."
echo "Now sourcing file \"$FILE_TO_SOURCE\"..."
. ${FILE_TO_SOURCE}
return
else
return 1
fi
}
main(){
if [ -z "$1" ]; then
showEnv; return
fi
case $1 in
-h) usage;;
*) setEnv $1;;
esac
return
}
PROG="chenv"
# create array of user-selectable environments
envList=( cold coles fc fcrm stable tip uat wellmdc )
main "$@"
return
If I could, I'd like to get some feedback on a better way to accomplish any of the following:
run through the case statement
make script trivally simple to maintain/upgrade/update
