Bash Remove Last Character From String / Line / Word

in Categories , , last updated April 12, 2014

I have a file of that looks as follows:

foo bar
tom jerry
UNIX Linux

Each word and/or Linux is a different length. How do strip or remove the last character from each line using bash or ksh shell only on a Linux or Unix-like systems?

You can use any one of the following commands:

  • Bash/ksh shell substitution
  • cut command
  • head command
  • tail command

Bash/ksh shell substitution example

The syntax to remove last character from line or word is as follows:

x="foo bar"
echo "${x%?}"

Sample outputs:

foo ba

The % is bash parameter substitution operators which remove from shortest rear (end) pattern. You can use the bash while loop as follows:

#!/bin/bash
while IFS= read -r line
do
       echo "${line%?}"
       # or put updated line to a new file
       #echo "${line%?}" >> /tmp/newfile
done < "/path/to/file"

cut command example

The syntax is as follows:

## if length of STRING is 3, pass 2 as  character positions 
echo "foo"| cut -c 1-2
## if length of STRING is 14, pass 13 as character positions 
echo "nixCraft Linux" | cut -c 1-13
See also:

# Additional correction by James K; Editing by VG – log #

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

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  3. Although a bit rude, the previous comment has a point: You can use head and tail to strip off characters. If you want it to be the first X or last X, you can use -/+, like so:

    echo '"foo!"'

    “foo!”

    echo '"foo!"' | head -c -2

    foo!”

    echo '"foo!"' | tail -c +2

    “foo!

    echo '"foo!"' | head -c -2 | tail -c +2

    foo!
    This is particularly useful with tree -Q (it doesn’t escape properly otherwise).

  4. Excellent, Keilaron !

    Just noticed a typo in your post (transposed cut paste):

    echo '"foo!"' | head -c -2
    “foo!

    echo '"foo!"' | tail -c +2
    foo!”

    1. Odd, I just updated and it still works for me.
      What do you get from head –version (which distro/OS, too)? I get head (GNU coreutils) 8.21 Packaged by Gentoo (8.21 (p1.0))…

      1. Mostly head/tail command on *BSD/OSX and older Unix-like oses will not accept GNU/{head|tail} syntax.

        1. Oh, good point. I even have an old Mac here I could have tested on, but I didn’t think of it. I was just thinking of Linux at the time.. and yeah, the GNU/Linux tools tend to have little quirks and additions.

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