Regular Expressions anyone?

I'm baffled! I've been reading, for days, about how to create regular
expressions.... and I'm lost. Can someone help me create RE's to do the
following?

1) Test a "Username" string. The string can contain 2 to 15 word
characters and hyphens but nothing else. I figured out /^\w{2,15}$/, but
how to I tell it hyphens are cool as well? I tried /^-?\w{2,15}-?$/, which
works if a hyphen starts or ends the string, but how can I tell it that
hyphens are okay anywhere in the middle, and still limit the total string
length to {2,15}?

2) If it fails, I'm telling the user that the username is invalid, and am
rejecting spaces embedded in the string (e.g., "user name" = false).
However, I'd rather just trim whitespace if it falls at the start or end of
the string before I test it, without bothering the user (e.g., trim("
username ") = "username", which would then test = true), but leave alone
whitespace in the middle (e.g., " user name " = "user name", which would
then test = false because of the space in the middle).

Thanks for your help!

Mike

"FunGuySF" <funguysfATpsmonopolyDOTorg> escribió en el mensaje
news:3oGdnbOZQrww8kLcRVn-3g (AT) comcast (DOT) com...

I'm baffled! I've been reading, for days, about how to create regular
expressions.... and I'm lost. Can someone help me create RE's to do the
following?

1) Test a "Username" string. The string can contain 2 to 15 word
characters and hyphens but nothing else. I figured out /^\w{2,15}$/, but
how to I tell it hyphens are cool as well? I tried /^-?\w{2,15}-?$/,
which works if a hyphen starts or ends the string, but how can I tell it
that hyphens are okay anywhere in the middle, and still limit the total
string length to {2,15}?

Try this one-line:

perl -e "$_=qq(5peter-john-l);print qq(MATCH) if (/^[\w-]{2,15}$/)"
MATCH

2) If it fails, I'm telling the user that the username is invalid, and am
rejecting spaces embedded in the string (e.g., "user name" = false).
However, I'd rather just trim whitespace if it falls at the start or end
of the string before I test it, without bothering the user (e.g., trim("
username ") = "username", which would then test = true), but leave alone
whitespace in the middle (e.g., " user name " = "user name", which would
then test = false because of the space in the middle).

Thanks for your help!

Mike

If you have Perl properly installed you can use the online help:

perldoc -q white
that gives you

$string =~ s/^\s+//; #trim starting white space
$string =~ s/\s+$//; #trim ending white space

Good luck! (Use the help, please!)

"Ociretsih Yahoo" <ociretsih (AT) yahoo (DOT) com> escribió en el mensaje
news:waPDd.45716$yo5.42333 (AT) twister (DOT) auna.com...

SORRY! A was thinking it was a Perl post!

SORRY again! I think this will fix my first wrong post
=====================================

I've seen a couple of web sites stating that:
---> The syntax of JavaScript RegEx's is the same as of Perl's
So, a little rewriting of my previous answer will suffice:

/*== JavaScript program ==*/
var myRE = /^[\w-]{2,15}$/;
var myString = "5peter-johnny-l";
var theResult;

if (myString.match(myRE))
{
theResult = "MATCHED";
} else
{
theResult = "UNMATCHED";
}

WScript.Echo(theResult); /* WARNING! This line is Microsoft's JScript
"standard output" - just delete it */
/*== End of JavaScript program ==*/

Thanks! That worked like a champ. I now understand how the []'s work.

I did figure out how to take care of the starting and trailing whitespace as
well, from your perl example.

Mike


"Ociretsih Yahoo" <ociretsih (AT) yahoo (DOT) com> wrote

SORRY again! I think this will fix my first wrong post
=====================================

I've seen a couple of web sites stating that:
---> The syntax of JavaScript RegEx's is the same as of Perl's
So, a little rewriting of my previous answer will suffice:

/*== JavaScript program ==*/
var myRE = /^[\w-]{2,15}$/;
var myString = "5peter-johnny-l";
var theResult;

if (myString.match(myRE))
{
theResult = "MATCHED";
} else
{
theResult = "UNMATCHED";
}

WScript.Echo(theResult); /* WARNING! This line is Microsoft's JScript
"standard output" - just delete it */
/*== End of JavaScript program ==*/