How to remove last n characters from a string in Bash?

Question

I have a variable var in a Bash script holding a string, like:

echo $var
\"some string.rtf\"

I want to remove the last 4 chara

Answer 1

Hope the below example will help,

echo ${name:0:$((${#name}-10))} --> ${name:start:len}

• In above command, name is the variable.
• start is the string starting point
• len is the length of string that has to be removed.

Example:

    read -p "Enter:" name
    echo ${name:0:$((${#name}-10))}

Output:

    Enter:Siddharth Murugan
    Siddhar

Note: Bash 4.2 added support for negative substring

Answer 2

You can do like this:

#!/bin/bash

v="some string.rtf"

v2=${v::-4}

echo "$v --> $v2"

Answer 3

Using Variable expansion/Substring replacement:

${var/%Pattern/Replacement}

If suffix of var matches Pattern, then substitute Replacement for Pattern.

So you can do:

~$ echo ${var/%????/}
some string

Alternatively,

If you have always the same 4 letters

~$ echo ${var/.rtf/}
some string

If it's always ending in .xyz:

~$ echo ${var%.*}
some string

You can also use the length of the string:

~$ len=${#var}
~$ echo ${var::len-4}
some string

or simply echo ${var::-4}

Answer 4

To remove four characters from the end of the string use ${var%????}.

To remove everything after the final . use ${var%.*}.