Send automatic predefined input variable parameters to a script called by another script in bash through command line prompt

If you want to run a bash script inside a bash script to automate it, but the inside bash script asks and waits for a keyboard input variable from the user to proceed, this tip will become handy.

$ ./your_bash_script1.sh
Welcome to the XYZ script
Would you like to rewrite the output files? Please input Y for yes or N for no

Now script waits for Y or N input from user. i.e you have to input Y or N to proceed. So if you want to put these script inside another bash script, you would have to enter is as many times and it asks. How to automate a predefined input, say Y, to it and sit lazy while the script does everything by itself and finishes off?. Try echo piping

#!/bin/bash
#Send automatic predefined input variable parameter to a script called by another script
#in bash through command line prompt in Linux.linux bash through command prompt
echo "Y" | ./your_bash_script1.sh
echo "N" | ./your_bash_script2.sh

This will take 'Y' as the user input for 'your_bash_script1.sh' and N for your_bash_script2.sh

Helpful commands for Linux cluster job management

qstat

qstat -a

qstat -an

qstat -f : to see full details of a job
gstat -a

finger
qdel

To kill all of your jobs: (queued and running)
for x in `qstat -a | grep 'username' | awk -F. {'print $1'}`;do qdel $x; done


To run a python program script command in a cluster node:


        ####################################################

        # /usr/bin/python   # XY run on linux cluster.
        # Run as $python XY-v1.0.py prg_script(.py)
        # Advantage of the scripts is that this can be used to run XY # in any node processor
        # of the cluster (or any linux cluster with PBS). But 1 job runs only on a single cpu

        import sys, posix, fileinput, string, re

        # XY path installed in your system
        path = "/XY/bin"
        stem = sys.argv[1]
        cwd = posix.getcwd()
        N = 0
        jobname = """%s""" % (stem)
        command = """echo "#PBS -l nodes=1

        #PBS -m ae
        #PBS -M your_e-mail
        #PBS -l walltime=3:00:00
        #PBS -l mem=512mb
        #PBS -S /bin/bash

        cd %s
        %s/bin/xy %s.py" > %s.j
        chmod +x %s.j
        qsub %s.j


        """ % (cwd, path, stem, jobname, jobname, jobname)
        posix.system(command)
         ####################################################

BASH script for reading input line by line from a list file and do a loop command

#! /bin/bash

cat file.lst |while read line; do scp "${line}" host:/directory_location; done

Colorful BASH prompt: How to display BASH prompt with multiple colors

Add this line to the .bashrc

PS1='\[$(tput bold)$(tput setb 4)$(tput setaf 7)\]\u@\h:\w $ \[$(tput sgr0)\] '


More references:

http://wiki.archlinux.org/index.php/Color_Bash_Prompt
http://www.systhread.net/texts/200703bashish.php
http://www.thegeekstuff.com/2008/09/bash-shell-ps1-10-examples-to-make-your-linux-prompt-like-angelina-jolie/
http://www.cyberciti.biz/faq/bash-shell-change-the-color-of-my-shell-prompt-under-linux-or-unix/

Useful Vi editor commands

VI Navigation  [escape key = ]
0  [zero] = Move to beginning of line
G         = Go to end of file
5G        = Move to beginning of 5th line
u         = Undo
.         = Repeat last command
x         = Delete character
dd        = Delete line
dw        = Delete word
d$        = Delete from cursor to end of line
$ then J  = Join/append following line with current
$ then a  = Append input at end of line
A         = Append input at end of line [same as above, but one less key stroke]
i         = Insert text at cursor
/         = Bottom of screen type search string and  will move 
                 cursor to first occurrence

Replace text

.  :1,$s /and/AND/g
   ^^^^^   ^   ^  ^
   |||||   |   |  |
   |||||   |   |  \----------- Globally
   |||||   |   \-------------- Replace with
   |||||   \------------------ Find
   |||||
   ||||\---------------------- substitute for text
   |||\----------------------- To last line
   ||\------------------------ separator
   |\------------------------- From line "1"
   \-------------------------- ":" operator to start command processing
Useful tid bit to remove EOL characters from DOS file 
[use key sequence "" together for EOL char]
 :%s/^M$//

Write lines to new file

:1,10w abc     [puts lines 1~10 into file abc]

Change working file from current to file abc [be sure to save first]

:e abc

Read abc file into working file after cursor

:r abc

Execute command from prompt

:!cmd    [where cmd is could be a bash command]

Example ->    :r !date   [inserts time and date at prompt]

From online wiki resource: http://en.wikibooks.org/wiki/Linux_Guide/Using_the_shell

Useful Linux command compilation

Set system date/time

: date -s "17 OCT 2010 13:00:00"

: hwclock -systohc


Change the time stamps of files

: touch foo


File Permissions

chmod -R ugoa =+- rwx filename
       ^ ^^^^ ^^^ ^^^     ^
       | |||| ||| |||     |
       | |||| ||| |||     \---------- file or directory
       | |||| ||| |||                 --------------------
       | |||| ||| ||\---------------- Execute
       | |||| ||| |\----------------- Write
       | |||| ||| \------------------ Read
       | |||| |||                     --------------------
       | |||| ||\-------------------- Remove
       | |||| |\--------------------- Add
       | |||| \---------------------- assign
       | ||||                         --------------------
       | |||\------------------------ All
       | ||\------------------------- Others
       | |\-------------------------- Group
       | \--------------------------- User
       |                              --------------------
       \----------------------------- Recursively 
                                      --------------------
       Usage: chmod g+w filename
 

From : http://en.wikibooks.org/wiki/Linux_Guide/Using_the_shell 

An excellent resource of information with clear explanations