Back Tics

Back Tics
Back tics are used with external commands to execute a command separately from the script and then be used by the script.  In this example the text string inside back tics is executed to create the variable.

Lesson 3 | Lesson 5

This script lists the name of the individual that is logged in.
sysname.sh

#!/bin/sh
SYSNAME=`egrep "^${USER}:" /etc/passwd | cut -d: -f5`
echo $SYSNAME

The system name for the user is grabbed by looking at the start of the line "^" for in /etc/passwd and then cut is used to cut out the fifth field.  Echo is used to express the system name which has become a variable, $SYSNAME.

Increase Your Knowledge About the cut Command

back tics - use in a statement where you want to substitute the command inside the back tics

forward tics - use in a statement where you do not want character or command substitution

double quotes - use in statement where you want to use character or command substitution