usage updated

cawk

@@ -43,18 +43,22 @@ There is NO WARRANTY, to the extent permitted by law.
 help="cawk ($version) - REPL calculator in Bash and AWK
 
 USAGE
+
   cawk [-f PRECISION]                 - Start in REPL mode.
   cawk -e EXPRESSION [-f PRECISION]   - Eval EXPRESSION and quit.
   COMMAND | cawk [-f PRECISION]       - Eval expressions from COMMAND output.
+  cawk [-f PRECISION] < FILE          - Eval expressions list in FILE
 
 OPTIONS
+
   -e EXPRESSION   Expression to evaluate.
   -f PRECISION    Number of positions after decimal point.
 
 COMMANDS
-  f[0-9]    Redefine precision.
-  h|?       Help.
-  q|quit    Quit.
+
+  f PRECISION   Redefine precision.
+  h or ?        Help.
+  q or quit     Quit.
 "
 
 # functions -------------------------------------------------------------------