Bash History: Correct / Repeat The Last Command With a Substitution

Posted on in Categories , , last updated February 23, 2016

I often type the wrong command as follows under Linux bash shell:

rsync -av dir1 [email protected]:/path/to/dir1

OR

cp -av file1*.txt file2*.txt /path/to/dest

I need to correct those command as follows:

rsync -av dir5 [email protected]:/path/to/dir1
cp -av delta1*.txt delta2*.txt /path/to/dest

How do I replace dir1 with dir5 or file with delta and repeat the last command under bash shell?

The bash shell supports both history search and replace operations. The bash (and many other modern) shell provides access to the command history, the list of commands previously typed. The bash shell supports a history expansion feature found in other shell such as csh.

Syntax: Bash history search and replace the command args

The syntax is as follows for quick substitution and repeat the last command, replacing word1 with word2:

^WORD1^WORD2^

OR

!!:s/WORD1/WORD2

OR

!!:gs/WORD1/WORD2

In this example, I’m trying to copy a file called youtube-demo-andriod-app-part1.avi to /backup directory
$ cp youtube-demo-andriod-app-part-102.avi /backup/
To repeat the last command with a substitution:
$ ^102^1002^
OR
$ !!:s/102/1002
Sample outputs:

cp youtube-demo-andriod-app-part-1002.avi /backup/

Please note that this substitutes only applies to the first occurrence. For example:
$ cp -av file1*.txt file2*.txt /path/to/dest
Replace file1 and file2 with delta1 and delta2, enter:
!!:gs/file/delta
Sample outputs:

cp -av delta1*.txt delta2*.txt /path/to/dest

You can also repeat the previous substitution with &:
cp -av file1*.txt file2*.txt /path/to/dest
!!:gs/file/delta-&/

Sample outputs:

cp -av delta-file1*.txt delta-file2*.txt /path/to/dest

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

7 comment

  1. Good stuff. Thanks for sharing!

    Don’t forget if it’s something as simple as replacing the first/last command, you can type CTRL+A to go to the beginning of the line and DEL the characters. CTRL+E goes to the end of the line. CTRL+W removes the last word. CTRL+U removes everything to the left of the cursor.

    1. “Why not just enter the following line into your .bash_profile? set -o vi”

      …because when you’re on a team of hundreds working on tens of thousands of servers, you have to learn how to deal with systems without special environment.

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