Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
line 2
EOF
# OUTPUT:
# line
# 1
# Thanks, S.C.
exit 0
[49] Filename expansion can match dotfiles, but only if the pattern explicitly includes the dot.
~/[.]bashrc
~/?bashrc
~/.[b]ashrc
~/.ba?hrc
~/.bashr*
# Will not expand to ~/.bashrc
# Neither will this.
# Wild cards and metacharacters will not expand to a dot in globbing.
# Will expand to ~./bashrc
# Likewise.
# Likewise.
# Setting the "dotglob" option turns this off.
# Thanks, S.C.
[50] This has the same effect as a named pipe (temp file), and, in fact, named pipes were at one time used in
process substitution.
[51] Indirect variable references (see Example 35−2) provide a clumsy sort of mechanism for passing
variable pointers to functions.
#!/bin/bash
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 "[$'$1'] "' # Previous value.
read local_var
[ −n "$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
Appendix J. Copyright 444