ceph-pr-submodules: add docs snippet for shell variables in foreach

Signed-off-by: Alfredo Deza <adeza@redhat.com>

diff --git a/ceph-pr-submodules/build/build b/ceph-pr-submodules/build/build
index 34a86d6c6559e48ba44a98b60381bcce3951a832..56c5fa18dbebe4105b7331f2725285a38485793d 100644 (file)
--- a/ceph-pr-submodules/build/build
+++ b/ceph-pr-submodules/build/build
@@ -1,6 +1,12 @@
 #!/bin/bash
 
 cd "$WORKSPACE"
+
+# The command below has access to the variables $name, $path, $sha1 and $toplevel:
+# $name is the name of the relevant submodule section in .gitmodules, $path is
+# the name of the submodule directory relative to the superproject, $sha1 is
+# the commit as recorded in the superproject, and $toplevel is the absolute
+# path to the top-level of the superproject.
 modified_submodules=$(git submodule foreach 'cd $toplevel; git diff --ignore-submodules=dirty origin/master -- $path')
 
 if [[ $modified_submodules ]]; then