tests/util/grub-shell: Allow specifying non-default trim line contents

This will be useful for tests that have unwanted output from setup. This is
not documented because its only intended to be internal at the moment. Also,
--no-trim is allowed to explicitly turn off trim.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

tests/util/grub-shell.in

@@ -32,6 +32,7 @@ PATH="${builddir}:$PATH"
 export PATH
 
 trim=0
+trim_head=664cbea8-132f-4770-8aa4-1696d59ac35c
 
 # Usage: usage
 # Print the usage.
@@ -226,8 +227,13 @@ for option in "$@"; do
 	echo "$0 (GNU GRUB ${PACKAGE_VERSION})"
 	exit 0 ;;
     --trim)
-	trim=1
+	trim=1 ;;
+    --trim=*)
+	trim=2
+	trim_head=`echo "$option" | sed -e 's/--trim=//' -e 's/,/ /g'`
 	;;
+    --no-trim)
+	trim=0 ;;
     --debug)
         debug=1 ;;
     --modules=*)
@@ -350,8 +356,6 @@ terminal_input ${term}
 terminal_output ${term}
 EOF
 
-trim_head=664cbea8-132f-4770-8aa4-1696d59ac35c
-
 if [ $trim = 1 ]; then
     echo "echo $trim_head" >>${cfgfile}
 fi
@@ -476,8 +480,8 @@ fi
 
 do_trim ()
 {
-    if [ $trim = 1 ]; then
-	awk '{ if (have_head == 1) print $0; } /664cbea8-132f-4770-8aa4-1696d59ac35c/ { have_head=1; }'
+    if [ $trim = 1 ] || [ $trim = 2 ]; then
+	awk '{ if (have_head == 1) print $0; } /'"$trim_head"'/ { have_head=1; }'
     else
 	cat
     fi