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:
for i in {1..10}; do commandNameHere; 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++)) do command1 command2 done |
The for loop syntax for tcsh / csh / ksh and other shell may changes from version to version. You can use python or Perl as follows to run date command 5 times:
#!/usr/bin/perl for $i (1 .. 5) { system("date"); } |
Python example:
#!/usr/bin/python # Run unix date command 3 times import os; for x in range(0,3): os.system("date") |
9 comment
I always forget the list iterator {1..10} syntax for bash. Thanks for the reminder!
Nice and useful article, indeed.
A litte note:
You said “For example, run UNIX date command five times, enter:”
and then shows: for i in {1..10}; do date; done
I mean: five times would be
for i in {1..5}; do date; done
But I know people understood what you’ve said.
Thanks again!
Thanks for the heads up!
Moin,
old style methods:
for i in $(seq 5);do date;done
for i in `seq 1 5`;do date;done
for i in 1 2 3 4 5;do date;done
for i in a b c d orwhatever;do date;done
at last some crazy unuseful (only work with dirs with more than 5 items)
for i in `ls /proc/*|head -n5`;do date;done
which is useful tool, repait command with delay
Hi.
I got this little function in my bash_aliases:
repeat() { local i n; n=$1; shift; for ((i=1; i<=n; i++)); do "$@"; done; }
then you can do # repeat 5 echo hey there
Hi,
I have another way to implement this.
just use seq and xargs
function __my_test { test $# -gt 1 && `seq 0 $1|xargs -i ${*#$1}`; }
Thanks for this :) Whenever I google something for linux/bash help I’m normally taken here XD
seq 20 | xargs commandName