UNIX for Advanced & Expert Users

#!/bin/sh
check() {
if [ ! -d ${1} ]; then
    echo "${1} is not a dir"; exit 1
fi
echo "{$1} is a directory"
}
# HOME is normally always defined for a process

check $HOME

$ cat xy
#! /usr/bin/ksh

check() {
name=$1
eval value=\$$1
echo the variable $name contains the value $value
if [ ! -d ${value} ]; then
echo "$value (which was passed in $name) is not a dir"
fi
echo dir
}
home=/u4/k
check home
home2=/something/else
check home2
exit 0
$ ./xy
the variable home contains the value /u4/k
/u4/k (which was passed in home) is not a dir
dir
the variable home2 contains the value /something/else
/something/else (which was passed in home2) is not a dir
dir
$