#!/bin/bash # ref-params.sh: Dereferencing a parameter passed to a function. # (Complex Example) ITERATIONS=3 # How many times to get input. icount=1 my_read () { # Called with my_read varname, #+ outputs the previous value between brackets as the default value, #+ then asks for a new value. local local_var echo -n "Enter a value " eval 'echo -n "[$'$1'] "' # Previous value. # eval echo -n "[\$$1] " # Easier to understand, #+ but loses trailing space in user prompt. read local_var [ -n "$local_var" ] && eval $1=\$local_var # "And-list": if "local_var" then set "$1" to its value. } echo while [ "$icount" -le "$ITERATIONS" ] do my_read var echo "Entry #$icount = $var" let "icount += 1" echo done # Thanks to Stephane Chazelas for providing this instructive example. exit 0
