Can a process be executed as a string in nextflow?
Nextflow processes can execute native code other than system scripts as shown in the previous paragraphs. This means that instead of specifying the process command to be executed as a string script, you can define it by providing one or more language statements, as you would do in the rest of the pipeline script.
How does a parallel approval workflow work?
In a parallel approval workflow, multiple persons are required to approve items such as invoices, purchase orders, vacation requests, etc. Each person’s approval is independent of all other approvers.
What kind of script is used in nextflow?
The process script is interpreted by Nextflow as a Bash script by default, but you are not limited to it. You can use your favourite scripting language (e.g. Perl, Python, Ruby, R, etc), or even mix them in the same pipeline.
What does the shell block do in nextflow?
The shell block is a string statement that defines the shell command executed by the process to carry out its task. It is an alternative to the Script definition with an important difference, it uses the exclamation mark ! character as the variable placeholder for Nextflow variables in place of the usual dollar character.
When to look for configuration files in nextflow?
When a pipeline script is launched, Nextflow looks for configuration files in multiple locations. Since each configuration file can contain conflicting settings, the sources are ranked to decide which settings to are applied. All possible configuration sources are reported below, listed in order of priority:
How is the name of a variable defined in nextflow?
The same mechanism allows you to access environment variables defined in the hosting system. Any variable whose name is not defined in the Nextflow configuration file (s) is supposed to be a reference to an environment variable with that name.