Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!sdd.hp.com!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: Changing the first character of a string.
Message-ID: <8569@jpl-devvax.JPL.NASA.GOV>
Date: 2 Jul 90 17:23:13 GMT
References: <1990Jul2.153957.24671@uvaarpa.Virginia.EDU>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 21

In article <1990Jul2.153957.24671@uvaarpa.Virginia.EDU> worley@compass.com writes:
: Of course, there's always:
: 
: 	$flags =~ s/^./U/;
: 
: (If $flags doesn't contain newlines, or $(whatever) is 0.)

If you want to avoid that problem, you can get fancy and say

	vec($flags,$offset,8) = ord('U');

That will extend the string as necessary.  (Of course, it'll extend it with
null characters if $offset is greater than the current length...)

You could also say

	$flags =~ s/^[^\0]?/U/;

But I still vote for substr.

Larry