====== Bash ======

====== Change the Shell Prompt ======
I found that particularly with Centos 5, that the default shell prompt for root was terrible. It did not show the pwd, user or host!

**Before**
 -bash-3.1# ls
Showing no present working directory, no current username, no hostname


**Syntax**
 PS1='\u@\h:\w\$ '
There are a few other things one can show also. Such as the time, date, FQHN etc. man bash for the full list.


**After**
 root@volcano:/tmp# ls

Ref.: http://www.builderau.com.au/program/linux/soa/10-shortcuts-to-master-bash/0,339028299,339279043,00.htm

====== Function problem in Bash ======
I recently dist-upgraded a ubuntu server, and one bash script stopped working.
==== Original =====
 #!/bin/bash
 
 watch '
 function yesno(){
 case "$1" in
        0)      echo "yes"
        ;;
        1)      echo "no"
        ;;
        *)      echo "error"
        ;;
 esac
 }

==== Problem ====
 sh: Syntax error: "(" unexpected

==== Solution ====
Remove the word function, and call it directly.

 #!/bin/bash
 
 watch '
 yesno(){
 case "$1" in
        0)      echo "yes"
        ;;
        1)      echo "no"
        ;;
        *)      echo "error"
        ;;
 esac
 }

Ref: http://stackoverflow.com/questions/6347119/bash-syntax-error