scripting.md

Shell scripting

The closh-zero.jar binary accepts same arguments as clojure.main CLI. That includes all features like aliases and deps. You can refer to the options with help:

closh-zero.jar --help

Running scripts

The most common way is running a one-off script by passing it as a command line argument like:

closh-zero.jar my-script.clj

Another common way is using the shebang:

#!/usr/bin/env closh-zero.jar

ls (first *args*)

Then you can make the script executable and run it like:

chmod +x my-script.clj
./myscript.clj

Writing scripts

Top-level commands can be written using the shell syntax:

#!/usr/bin/env closh-zero.jar

echo "Working..."
sleep (rand-int 5)
echo "Done"

When you need to need to use the commands inside conditionals or functions, wrap them in a sh macro. Individual commands need to be separated with \;.

#!/usr/bin/env closh-zero.jar

(defcmd do-work [interval]
  (sh echo "Working..." \;
      sleep (str interval) \;
      echo "Done"))

do-work (rand-int 5)

Using arguments

To use CLI arguments you can use the *args* alias, which is a sequence of arguments passed by user.

#!/usr/bin/env closh-zero.jar

echo "Number of arguments:" (count *args*)

For parsing command line arguments tools.cli works great. It is also possible to use any other library.

Examples

As an example I ported gifgen utility to closh. Compare the original bash version with the closh version.