better explanations

README.md

@@ -8,7 +8,7 @@ A command line tool that call the given command for each input line matching the
 
 `paternoster` [-h]
 
-`paternoster` [-w] [-e] PATTERN COMMAND(S)
+`paternoster` [-w] [-e] [-g] PATTERN COMMAND(S)
 
 
 ## DESCRIPTION
@@ -32,15 +32,21 @@ duplicated across remaining groups.
 
 * `-w`, `--nowait`:
   Don't wait for the end of the current command before calling the next one.
+  This will call commands as soon as they are met in the stream, 
+  If the stream is read fast, commands will most probably be ran quasi-simultaneously.
 
 * `-e`, `--end`:
   Run commands at the end of the input stream.
+  Note that if the stream don't end (for example if you input from `tail -f`),
+  nothing will be done until an interruption.
 
 * `-g`, `--group`:
   Capture groups as arguments for the CMD, instead of running CMD for each group.
   CMD must have as many formating placeholder as captured groups.
   For example, if you capture 3 groups, you must put 3 formating placeholders in CMD:
     `paternoster --group "^(.*):(.*):(.*)$" "echo '>>> 1:%s 2:%s 3:%s <<<'"`
+  If placeholders count does not match the groups count, no substitution is made
+  and the placeholders are left as is.
 
 
 ## EXAMPLES

paternoster.py

@@ -93,11 +93,6 @@ def read_parse( stream_in, stream_out, pattern, cmd, nowait = False, at_end = Fa
     Read the given file-like object as a non-blocking stream
     and call the function on each item (line),
     with the given extra arguments.
-
-    A call to "map_write(sys.stdin, function, *args)" will translate to the
-    non-blocking equivalent of:
-        for item in sys.stdin.readlines():
-            write( function( *args ) )
     """
 
     if at_end:
@@ -138,7 +133,6 @@ if __name__ == "__main__":
             help="A regular expression")
 
     parser.add_argument("commands", metavar="CMD", type=str, nargs="+",
-            default="espeak %s",
             help="The command to run if REGEX match. \
             If CMD contains a string formating placefolder (like \"%%s\"), \
             it will be replaced by the matching text. \