Scripting variables

One of the major strengths of Viash is its automatic code generation. The generated variables can be accessed in your scripts.

Tip: You can use the viash config inject command to add all arguments from your Viash config file to your script automatically, together with the meta variables.

Config arguments #

Any arguments you added to the functionality section of the Viash config file can be used in your scripts.

functionality:
  ...
  arguments:
  - type: string
    name: input
  ...

The input argument in the example above here can be called in different ways depending on the scripting language.

Bash:

echo $par_input

Python:

print(par["input"])

R example:

cat(par$input)

Javascript:

console.log(par['input']);

Scala:

println(par.input)

C#:

Console.WriteLine(par.input);

Meta variables #

Viash offers some hidden variables to use in your scripts that can be used to get meta information about your component.

Functionality name #

Name of the component found in the functionality section of the Viash config. Example: my_component_name.

Examples #

Bash:

echo $meta_functionality_name

Python:

print(meta["functionality_name"])

R example:

cat(meta$functionality_name)

Javascript:

console.log(meta['functionality_name']);

Scala:

println(meta.functionality_name)

C#:

Console.WriteLine(meta.functionality_name);

Resources directory #

Path where the resources as defined in the config file are stored. Example: /home/user/output/resources.

Examples #

Bash:

echo $meta_resources_dir

Python:

print(meta["resources_dir"])

R example:

cat(meta$resources_dir)

Javascript:

console.log(meta['resources_dir']);

Scala:

println(meta.resources_dir)

C#:

Console.WriteLine(meta.resources_dir);

Temp directory #

Path to the directory supplied by the host system where you can write temporary files to. Example: /tmp.

Examples #

Bash:

echo $meta_temp_dir

Python:

print(meta["temp_dir"])

R example:

cat(meta$temp_dir)

Javascript:

console.log(meta['temp_dir']);

Scala:

println(meta.temp_dir)

C#:

Console.WriteLine(meta.temp_dir);