In Linux, you can use xargs -d, to quickly run the hostname command against four different servers with sequential names as follows:

echo -n 1,2,3,4 |xargs -d, -I{} ssh root@www{}.example.com hostname

It looks like the OSX xargs command does not support the delimiter parameter. Can you achieve the same result with a differently formatted echo, or through some other command-line utility?


How about:

echo {1..4} | xargs -n1 -I{} ssh root@www{}.example.com hostname

From man xargs:

-n number
Set the maximum number of arguments taken from standard input for each invocation of utility.
  • 1
    If the values can contain spaces, linefeeds, or tabs, you could use something like printf 'a\0a' | xargs -0 -n1 echo. – Lri Oct 18 '12 at 7:20

Alternatively, you can always install GNU xargs through Homebrew and the GNU findutils package.

Install Homebrew:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

Follow the instructions. Then install findutils:

brew install findutils

This will give you GNU xargs as gxargs, and you can use the syntax you're accustomed to from GNU/Linux. The same goes for other basic commands found in the findutils package such as gfind or glocate or gupdatedb, which have different BSD counterparts on OS X.

  • Thank you! I did this, then added the path to my .zshrc (as explained in the installation output) so I wouldn't have to use the g prefix. – absynce Aug 15 '19 at 18:25
  • ha yiss exactly what I was looking for – Jean-Bernard Jansen Apr 24 '20 at 13:24

You can also use tr in OSX to convert the commas to new lines and use xargs to enumerate through each item as follows:

echo -n 1,2,3,4 | tr -s ',' '\n' | xargs -I{} ssh root@www{}.example.com hostname

If you want it run in parallel, use GNU Parallel:

parallel ssh root@www{}.example.com hostname ::: {1..4}

with printf

$ printf '%s\n' 1 2 3 4 | xargs -I{} echo ssh root@www{}.example.com hostname
ssh root@www1.example.com hostname
ssh root@www2.example.com hostname
ssh root@www3.example.com hostname
ssh root@www4.example.com hostname

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