You can upload and run a bash script in your Mitto command jobs.

Bash, the most commonly available unix shell, is

the shell, or command language interpreter, for the GNU operating system.

Bash commands can be saved in a file and executed as a script.

The following Bash script (test_bash_script.sh) creates a CSV file: written_by_bash.csv

#!/bin/bash

echo "id, name" > /var/mitto/data/written_by_bash.csv
echo "1, Allen" >> /var/mitto/data/written_by_bash.csv
echo "2, Steve" >> /var/mitto/data/written_by_bash.csv

Upload the Bash script to Mitto via the file manager (in the menu on the left).

{
    "cmd": "bash /var/mitto/data/test_bash_script.sh",
    "shell": true
}

Then create a cmd  job. Give it a name, and use the JSON above. The job type needs to be set to cmd (in the green circle below).

Running the job should create a file that looks like this: