Script execution actions

• Difficulty level: easy
• Time need to lean: 10 minutes or less
  • Action script is a general script execution action
  • Actions such as Python2, Python3, Perl executes scripts with specified interpreters

Action script

Action script is the general form of all script-executing actions in SoS. It accepts a script, and parameters interpreter (required), suffix (if required by the interpreter) and optional args (command line arguments). It can be used to execute any script for which its interpreter is not currently supported by SoS. For example, the action

python:
    print('HERE')

can be executed as

Action perl

Action perl executes the passed script using perl interpreter.

Action ruby

Action ruby execute the passed script using ruby interpreter.

Action node

Action node executes the passed script using node (JavaScript) interpreter.

Action julia

Action julia execute specified Julia script with command julia. Because my system does not have julia installed, the following example executes a Julia script in a docker container.

Action matlab

Action matlab execute specified matlab script with default options -nojvm -nodisplay -nosplash -r {filename:n};quit. The options start matlab without desktop, execute the strip (with parameter without .m extension), and quit matlab when the script is completed.

Action python

Action python and python3 accepts a Python script and execute it with python or python3, respectively.

Because SoS can include Python statements directly in a SoS script, it is important to note that embedded Python statements are interpreted by SoS and the python and python3 actions are execute in separate processes without access to the SoS environment.

For example, the following SoS step execute some python statements within SoS with direct access to SoS variables such as input, and with result writing directly to the SoS environment,

[10]
for filename in input:
    with open(filename) as data:
        result = filename + '.res'
        ....

while

[10]
input: group_by='single'

python:

with open(${input!r}) as data:
   result = ${input!r} + '.res'
   ...

composes a Python script for each input file and calls separate Python interpreters to execute them. Whereas the Python statement in the first example will always be executed, the statements in python will not be executed in inspect mode.

In the following example, python actually calls Python 3 because version 3 is the default python interpreter on my system.

Action python2

Action python2 is similar to python but it tries to use interpreter python2 (or python2.7 on some systems) before python, which could be python 3. Note that this action does not actually test the version of interpreter so it would use python 3 if this is the only available version.

Action python3

Action python3 is similar to python but it tries to use interpreter python3 (version 3 of python) before python, which could be python 2. Note that this action does not actually test the version of interpreter so it would use python 2 if this is the only available version.

Action R

Action R(script) execute the passed script using Rscript command.

Parameter entrypoint

You can use parameter entrypoint to change the environment in which the interpreter will be executed. An entrypoint is usually the name of a shell script that defines a number of environment variables and run the command given by the command line parameters in such a way that the current process is replaced by it,

#!/bin/bash

set -o errexit
set -o pipefail
set -o nounset

export MY_ENV=MY_VALUE

exec "$@"

but it can also be other commands such as micromamba run -n ENVIRONMENT.

For example, the following statement will execute interpreter Rscript

It's equivalent to the following statement