HowTo Display Text Files In a Shell Script

I am a new Unix user and learning bash shell scripting. How do I display a text file stored in /tmp directory in a shell script?

There are many ways to display a text file in a shell script. You can simply use the cat command and display back output on screen. Another option is to read a text file line by line and display back the output. In some cases you may need to store output to a variable and later display back on screen.

Task: Display output using the cat command

Following sample script displays contents of a file called /tmp/input.txt:

#!/bin/bash
FILE="/tmp/input.txt"
echo "*** File - $FILE contents ***"
cat $FILE

Task: Store a file output in a variable

Following sample script displays nameserver IPs:

#!/bin/bash
FILE="/etc/resolv.conf"
OUT=$(awk '{ print $2 }' $FILE)
echo "*** Nameserver IP ***"
for ip in $OUT
do
   echo $ip
done

Task: Read a text file line-by-line

See our previous tutorial for more information:

1. Linux/ UNIX: Read a File Line By Line
2. Linux / Unix AWK: Read a Text File
3. HowTo: Bash For While Loop Through File Contents Script
4. Ksh Read a File Line By Line ( UNIX Scripting )