while loop – nixCraft

Shell Script To Count Vowels, Blank Spaces, Characters, Number of line and Symbols

in Academic, Decision Making, String Management last updated February 20, 2009

Shell program to count Vowels, blank spaces, characters, number of line and symbols from a file.

Shell Script To Simulate UNIX More Command To Display Only The 15 Lines At A Time

in File-management, String Management last updated September 20, 2008

UNIX / Linux shell script like a more command. It asks the user name, the name of the file on command prompt and displays only the 15 lines of the file at a time.

Shell Script To Delete All Even Numbered Line From a Text File

in Academic, Decision Making, File-management last updated September 17, 2008

UNIX shell script which deletes all even numbered line from a text file.

Shell Script To Write Odd and Even Line To Respective Files

in Academic, Decision Making, File-management last updated September 17, 2008

A shell script that, given a file name as the argument will write the even numbered line to a file with name evenfile and odd numbered lines in a text file called oddfile.

Shell Script To Count English Language Articles Such As 'A', 'An' and 'The'

in Decision Making, File-management last updated April 21, 2008

This script also covers following techniques:
=> Reading input text file line by line
=> Reading and processing words in input
=> Convert word to lowercase

#!/bin/bash
# Write a shell script that counts English language articles (a, an, the) 
# in a given text file.
#
# --------------------------------------------------------------------
# This is a free shell script under GNU GPL version 2.0 or above
# Copyright (C) 2005 nixCraft project.
# Feedback/comment/suggestions : http://cyberciti.biz/fb/
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
echo -n "Enter a file name : "
read file
a=0
the=0
an=0

# make sure file exist
if  [ ! -f $file ]
then
	echo "$file not a file!"
	exit 1
fi

# put while loop to read a $file
while read line
do
       #process each word 
	for w in $line 
	do
		# convert word to lowercase; so that we can count ThE, THE, the, THe etc all
		lword="$(echo $w | tr '[A-Z]' '[a-z]')"

		# is it 'a' article?
		[ $lword = "a" ] && (( a++ )) || :
		[ $lword = "the" ] && (( the++ )) || :
		[ $lword = "an" ] && (( an++ )) || :
	done
done < $file

# display stats
echo "a article occured $a times"
echo "the article occured $the times"
echo "an article occured $an times"

#!/bin/bash

# Write a shell script that counts English language articles (a, an, the)

# in a given text file.

# --------------------------------------------------------------------

# This is a free shell script under GNU GPL version 2.0 or above

# Feedback/comment/suggestions : http://cyberciti.biz/fb/

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

echo -n "Enter a file name : "

read file

a=0

the=0

an=0

# make sure file exist

if [ ! -f $file ]

then

echo "$file not a file!"

exit 1

# put while loop to read a $file

while read line

#process each word

for w in $line

# convert word to lowercase; so that we can count ThE, THE, the, THe etc all

lword="$(echo $w | tr '[A-Z]' '[a-z]')"

# is it 'a' article?

[ $lword = "a" ] && (( a++ )) || :

[ $lword = "the" ] && (( the++ )) || :

[ $lword = "an" ] && (( an++ )) || :

done

done < $file

# display stats

echo "a article occured $a times"

echo "the article occured $the times"

echo "an article occured $an times"

Shell Script To Monitor Services Such As Web / Http, Ssh, Mail Server

in Monitoring last updated July 14, 2009

A Linux / UNIX Shell Script To Monitor Services Such As Web / Http, Ssh, Mail Server and send an email if they are down.

Monitor UNIX / Linux Server Disk Space with Shell Script

in Monitoring last updated April 10, 2008

Shell script to monitor or watch the disk space and send an email alert if the (free avilable) percentage of space is >= 90%

#!/bin/sh
# Shell script to monitor or watch the disk space
# It will send an email to $ADMIN, if the (free avilable) percentage 
# of space is >= 90% 
# -------------------------------------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# ----------------------------------------------------------------------
# Linux shell script to watch disk space (should work on other UNIX oses )
# SEE URL: http://www.cyberciti.biz/tips/shell-script-to-watch-the-disk-space.html
# set admin email so that you can get email
ADMIN="me@somewher.com"
# set alert level 90% is default
ALERT=90
df -H | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;
do
  #echo $output
  usep=$(echo $output | awk '{ print $1}' | cut -d'%' -f1  )
  partition=$(echo $output | awk '{ print $2 }' )
  if [ $usep -ge $ALERT ]; then
    echo "Running out of space \"$partition ($usep%)\" on $(hostname) as on $(date)" | 
     mail -s "Alert: Almost out of disk space $usep" $ADMIN
  fi
done

#!/bin/sh

# Shell script to monitor or watch the disk space

# It will send an email to $ADMIN, if the (free avilable) percentage

# of space is >= 90%

# -------------------------------------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# ----------------------------------------------------------------------

# Linux shell script to watch disk space (should work on other UNIX oses )

# SEE URL: http://www.cyberciti.biz/tips/shell-script-to-watch-the-disk-space.html

# set admin email so that you can get email

ADMIN="me@somewher.com"

# set alert level 90% is default

ALERT=90

df -H | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;

#echo $output

usep=$(echo $output | awk '{ print $1}' | cut -d'%' -f1 )

partition=$(echo $output | awk '{ print $2 }' )

if [ $usep -ge $ALERT ]; then

echo "Running out of space \"$partition ($usep%)\" on $(hostname) as on $(date)" |

mail -s "Alert: Almost out of disk space $usep" $ADMIN

done

Bash shell script to reverse text file contain using Shell array

in File-management last updated July 24, 2008

This script also demonstrate how to use arrays under bash shell script.

#!/bin/bash
# Bash shell script to reverse text file contain i.e. concatenate files and
# print on the standard output in reverse. This script also demonstrate how 
# to use arrays under bash shell script.
# -------------------------------------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
FILE="$1"
if [ $# -eq 0 ]; then
  echo "$(basename $0) - file-name"
  exit 1
fi

textArray[0]="" # hold text
c=0 # counter 
# read whole file in loop
while read line
do
  textArray[$c]=$line # store line
  c=$(expr $c + 1) # increase counter by 1
done < $FILE
# get length of array 
len=$(expr $c - 1 )

# use for loop to reverse the array
for (( i=$len; i>=0; i-- ));
do
  echo ${textArray[$i]}
done

#!/bin/bash

# Bash shell script to reverse text file contain i.e. concatenate files and

# print on the standard output in reverse. This script also demonstrate how

# to use arrays under bash shell script.

# -------------------------------------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

FILE="$1"

if [ $# -eq 0 ]; then

echo "$(basename $0) - file-name"

exit 1

textArray[0]="" # hold text

c=0 # counter

# read whole file in loop

while read line

textArray[$c]=$line # store line

c=$(expr $c + 1) # increase counter by 1

done < $FILE

# get length of array

len=$(expr $c - 1 )

# use for loop to reverse the array

for (( i=$len; i>=0; i-- ));

echo ${textArray[$i]}

done

Script utility to read a file line line and separate line in fields

in File-management last updated April 9, 2008

Script utility to read a file line line version 2. This is simpler version of readline script, it also demonstrate how to process text data file line by line and then separate line in fields, so that you can process it according to your need.

#!/bin/bash
# 
# Shell script utility to read a file line line version 2
# This is simpler version of readline script
# This script also demonstrate how to process data file 
# line by line and then separate line in fields, so that 
# you can process it according to your need. 
# 
# You can call script as follows
# ./readline2
# -----------------------------------------------
# Copyright (c) 2005 nixCraft <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

### Main script stars here ###
# Store file name  here
FILE="/etc/passwd"
# field seprator, default is :, you can use blank space or
# other character, if you have more than one blak space in
# input line then use awk utility and not the cut :)
FS=":"

while read line
do
	# store field 1
	F1=$(echo $line|cut -d$FS -f1)
	# store field 2
	F2=$(echo $line|cut -d$FS -f6)
	# store field 
	F3=$(echo $line|cut -d$FS -f7)
	echo "User \"$F1\" home directory is $F2 and login shell is $F3"
done < $FILE

#!/bin/bash

# Shell script utility to read a file line line version 2

# This is simpler version of readline script

# This script also demonstrate how to process data file

# line by line and then separate line in fields, so that

# you can process it according to your need.

# You can call script as follows

# ./readline2

# -----------------------------------------------

# This script is licensed under GNU GPL version 2.0 or above

# -------------------------------------------------------------------------

# This script is part of nixCraft shell script collection (NSSC)

# Visit http://bash.cyberciti.biz/ for more information.

# -------------------------------------------------------------------------

### Main script stars here ###

# Store file name here

FILE="/etc/passwd"

# field seprator, default is :, you can use blank space or

# other character, if you have more than one blak space in

# input line then use awk utility and not the cut :)

FS=":"

while read line

# store field 1

F1=$(echo $line|cut -d$FS -f1)

# store field 2

F2=$(echo $line|cut -d$FS -f6)

# store field

F3=$(echo $line|cut -d$FS -f7)

echo "User \"$F1\" home directory is $F2 and login shell is $F3"

done < $FILE