added comments about [[ ]] to ash and hush. no code changes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 10 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 7843afa..c726ad4 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -8736,6 +8736,11 @@ static int ulimitcmd(int, char **) FAST_FUNC;
  * Additional operators:
  * || and && should work as -o and -a
  * =~ regexp match
+ * == should do _pattern match_ against right side. bash does this:
+ *      # [[ *a* == bab ]] && echo YES
+ *      # [[ bab == *a* ]] && echo YES
+ *      YES
+ * != does the negated == (i.e., also with pattern matching)
  * Apart from the above, [[ expr ]] should work as [ expr ]
  */
 
diff --git a/shell/hush.c b/shell/hush.c
index 54ab78b..245fb58 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -318,6 +318,11 @@ struct command {
 // Additional operators:
 // || and && should work as -o and -a
 // =~ regexp match
+// == should do _pattern match_ against right side. bash does this:
+//      # [[ *a* == bab ]] && echo YES
+//      # [[ bab == *a* ]] && echo YES
+//      YES
+// != does the negated == (i.e., also with pattern matching)
 // Apart from the above, [[ expr ]] should work as [ expr ]
 
 /* used for "export noglob=* glob* a=`echo a b`" */