Bash-Beginners-Guide

[carol@octarine ~/test] ls -a
./ ../ test test~
The tr is part of the textutils package; it can perform all kinds of character transformations.
9.6. Making menus with the select built-in
9.6.1. General
9.6.1.1. Use of select
The select construct allows easy menu generation. The syntax is quite similar to that of the for loop:
select WORD [in LIST]; do RESPECTIVE-COMMANDS; done
LIST is expanded, generating a list of items. The expansion is printed to standard error; each item is preceded
by a number. If in LIST is not present, the positional parameters are printed, as if in $@ would have been
specified. LIST is only printed once.
Upon printing all the items, the PS3 prompt is printed and one line from standard input is read. If this line
consists of a number corresponding to one of the items, the value of WORD is set to the name of that item. If
the line is empty, the items and the PS3 prompt are displayed again. If an EOF (End Of File) character is
read, the loop exits. Since most users don't have a clue which key combination is used for the EOF sequence,
it is more user-friendly to have a break command as one of the items. Any other value of the read line will set
WORD to be a null string.
The read line is saved in the REPLY variable.
The RESPECTIVE-COMMANDS are executed after each selection until the number representing the break
is read. This exits the loop.
9.6.1.2. Examples
Bash Guide for Beginners
This is a very simple example, but as you can see, it is not very user-friendly:
[carol@octarine testdir] cat private.sh
#!/bin/bash
echo "This script can make any of the files in this directory private."
echo "Enter the number of the file you want to protect:"
select FILENAME in *;
do
echo "You picked $FILENAME ($REPLY), it is now only accessible to you."
chmod go-rwx "$FILENAME"
done
[carol@octarine testdir] ./private.sh
This script can make any of the files in this directory private.
Enter the number of the file you want to protect:
1) archive-20030129
2) bash
3) private.sh
#? 1
Chapter 9. Repetitive tasks 117