Invoke with command line parameter to exercise last section of this script
#!/bin/bash # Invoke with command line parameter to exercise last section of this script. shopt -s expand_aliases # Must set this option, else script will not expand aliases. # First, some fun. alias Jesse_James='echo "\"Alias Jesse James\" was a 1959 comedy starring Bob Hope."' Jesse_James echo; echo; echo; alias ll="ls -l" # May use either single (') or double (") quotes to define an alias. echo "Trying aliased \"ll\":" ll /usr/X11R6/bin/mk* #* Alias works. echo directory=/usr/X11R6/bin/ prefix=mk* # See if wild-card causes problems. echo "Variables \"directory\" + \"prefix\" = $directory$prefix" echo alias lll="ls -l $directory$prefix" echo "Trying aliased \"lll\":" lll # Long listing of all files in /usr/X11R6/bin stating with mk. # Alias handles concatenated variables, including wild-card o.k. TRUE=1 echo if [ TRUE ] then alias rr="ls -l" echo "Trying aliased \"rr\" within if/then statement:" rr /usr/X11R6/bin/mk* #* Error message results! # Aliases not expanded within compound statements. echo "However, previously expanded alias still recognized:" ll /usr/X11R6/bin/mk* fi echo count=0 while [ $count -lt 3 ] do alias rrr="ls -l" echo "Trying aliased \"rrr\" within \"while\" loop:" rrr /usr/X11R6/bin/mk* #* Alias will not expand here either. # alias.sh: line 57: rrr: command not found let count+=1 done echo; echo alias xyz='cat