stderr | WDL Specification

File stderr()

Returns the value of the executed command's standard error (stderr) as a File. The file should be given a random name and written in a temporary directory, so as not to conflict with any other task output files.

Parameters: None

Returns: A File whose contents are the stderr generated by the command of the task where the function is called.

Example: echo_stderr_task.wdl

version 1.3

task echo_stderr {
  command <<< >&2 printf "hello world" >>>

  output {
    String message = read_string(stderr())
  }
}

Example input:

{}

Example output:

{
  "echo_stderr.message": "hello world"
}