Merge pull request #227 from common-workflow-language/stderr

add stderr object to draft-4

Author: mr-c

draft-4/CommandLineTool.yml

@@ -434,6 +434,18 @@ $graph:
       doc: |
         A path to a file whose contents must be piped into the command's
         standard input stream.
+    - name: stderr
+      type: ["null", string, "#Expression"]
+      doc: |
+        Capture the command's standard error stream to a file written to
+        the designated output directory.
+
+        If `stderr` is a string, it specifies the file name to use.
+
+        If `stderr` is an expression, the expression is evaluated and must
+        return a string with the file name to use to capture stderr.  If the
+        return value is not a string, or the resulting path contains illegal
+        characters (such as the path separator `/`) it is an error.
     - name: stdout
       type: ["null", string, "#Expression"]
       doc: |

draft-4/conformance_test_draft-4.yaml

@@ -44,6 +44,12 @@
   tool: draft-4/cat3-tool.cwl
   doc: Test command line with stdout redirection
 
+- args: [egrep]
+  stderr: error.txt
+  job:
+  tool: draft-4/egrep-stderr.cwl
+  doc: Test command line with stdout redirection
+
 - args: [cat]
   job: draft-4/cat-job.json
   stdin: draft-4/hello.txt