Month: May 2012

As most of you know, we can define variables in our shell scripts to make our scripts more independent of hard coding. Below are they ways we can assign values to variables in a shell script Defining variables in the script: Assigning predefined constants to variables with the script. Before executing a script: Using positional parameters we can assign values to variables before actual execution of the script When running a script: We can assign values to variables when we are in middle of the script. All these solve different purposes on when to assign values to variables. The read command is useful for assigning variables at the time of executing a script, a kind of interactive script. Learn read command with examples The read command syntax read VARIABLE_NAME To access the above variable we use “$” or use echo if you want to print it. echo "My variable is $VARIABLE_NAME" Some frequently used read command examples Example1: Read a value from user input. To display this value, we have to use echo command as mention earlier. read VAR1 echo $VAR1 Output: surendra@sanne-taggle:~$ read VAR1 surendra surendra@sanne-taggle:~$ echo $VAR1 surendra Example2: The read command is an excellent command which can read two or more words/variable/values at a time. read VAR1 VAR2 Output: surendra@sanne-taggle:~$ read VAR1 VAR2 surendra kumar surendra@sanne-taggle:~$ echo $VAR1 surendra surendra@sanne-taggle:~$ echo $VAR2 kumar Example3: We can use read...