Linux / UNIX: Run Command a Number of Times In a Row

Linux / UNIX: Run Command a Number of Times In a Row

last updated in Categories , ,


How do I run “foo” command 10 times (or n times) under Linux or UNIX like operating systems?

You can use bash shell loop (run code or command repeatedly) to run a command 10 times as follows.
How to run a command N times in bash
there are many ways to run a command N times in bash/ksh/zsh. Use syntax as per your shell.





The syntax is:

## run command 10 times 
for i in {1..10}; do commandNameHere; done
## run script 20 times
for i in {1..10}; do /path/to/; done

For example, run UNIX date command five times, enter:

for i in {1..5}; do date; done

You can also use c like bash for loop syntax:

for ((n=0;n<5;n++))

The for loop syntax for tcsh / csh / ksh and other shell may changes from version to version.

Using while loop

Use the bash/sh/ksh posix based while loop as follows:

## define end value ##
## print date five times ##
while [ $x -gt 0 ]; 

repeat for zsh users

If you are using the Z shell (zsh)

repeat N { command }
repeat N { /path/to/script }
## print date five times on screen ##
repeat 5 { date }

Say hello to seq command

To print a sequence of numbers one can use the seq command too. The syntax is:
seq LAST
seq LAST | xargs command
seq FIRST LAST | xargs command
seq FIRST INCREMENT LASE | xargs command

To just print five number, run:
$ seq 1 5
$ seq 5
Sample outputs:


Use the xargs command to run the date command five times:
$ seq 1 5 | xargs -I{} date
Sample outputs:

Tue Nov 28 00:32:52 IST 2017
Tue Nov 28 00:32:52 IST 2017
Tue Nov 28 00:32:52 IST 2017
Tue Nov 28 00:32:52 IST 2017
Tue Nov 28 00:32:52 IST 2017

You can use xargs with multiple commands line argument as follows:
$ seq 1 5 | xargs -I{} sh -c "date && sleep 1"
It is also possible to use the parallel command:
$ seq 5 | parallel 'echo {}'
$ seq 5 | parallel 'echo Hello $USER, {} times.'

See man page of the following command for more info:
$ man parallel
$ man xargs
$ man seq

A note about using Perl or Python

You can use python or Perl as follows to run date command 5 times:

for $i (1 .. 5) {

Python example:

# Run unix date command 3 times 
import os;
for x in range(0,3):
0 (0)
Article Rating (No Votes)
Rate this article
There are no attachments for this article.
There are no comments for this article. Be the first to post a comment.
Full Name
Email Address
Security Code Security Code
Related Articles RSS Feed
How to Migrate from RHEL 8 to CentOS 8
Viewed 104 times since Fri, May 15, 2020
How To Add Swap Space on Ubuntu 16.04
Viewed 541 times since Fri, Jun 8, 2018
Jak wygenerować silne hasła jednorazowe w Linuksie?
Viewed 855 times since Thu, May 24, 2018
linux aix Killing a process and all of its descendants
Viewed 137 times since Tue, May 5, 2020
YUM How to use yum command on CentOS/RHEL
Viewed 2067 times since Thu, Oct 25, 2018
Viewed 500 times since Fri, Jul 27, 2018
How to deal with dmesg timestamps
Viewed 541 times since Wed, Oct 3, 2018
List usernames instead of uids with the ps command for long usernames
Viewed 470 times since Wed, Jul 25, 2018
Viewed 1765 times since Sat, Jun 2, 2018
RHEL: What is "SysRq key" and how to use it
Viewed 1286 times since Sat, Jun 2, 2018