i wann get some character from a string

weihe has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: i wann get some character from a string by GrandFather (Saint) on Aug 02, 2006 at 03:32 UTC
Generally we like to see a little effort rather than "write this code for me". Show us what you have tried so far. If you haven't tried anything take a look at the Tutorials section here and at the Pattern Matching, Regular Expressions, and Parsing section in particular. You should also look at perlretut, perlrequick, perlre and perlreref. If you still have trouble after that come back with your attempted code and ask again. DWIM is Perl's answer to Gödel	[reply]
Re: i wann get some character from a string by McDarren (Abbot) on Aug 02, 2006 at 03:33 UTC
"..how can i write a regular expressions for this .." If you wish to learn about regular expressions, then probably the two best places to start are with perlre and perlretut. If you are really serious about learning regular expressions, then you'll be wanting a copy of the Owl. Cheers, Darren	[reply]
Re^2: i wann get some character from a string by weihe (Initiate) on Aug 02, 2006 at 08:25 UTC
thanks for your advise me, i will follow you to learnning regular expressions	[reply]
Re: i wann get some character from a string by GhodMode (Pilgrim) on Aug 02, 2006 at 03:44 UTC
If you really want to use a regular expression for this, it would be something like `/^.?=(.)$/`. After that regex, $1 would hold your ID. A regular expression isn't the right tool for that. Regular expressions can be expensive in terms of efficiency. So, you should favor other methods when possible. For those strings use split ... `use strict; use warnings; my @strings = ( "http://mysite/bbsui.jsp?id=dxpwd", "http://mysite/bbsui.jsp?id=dxpsf", "http://mysite/bbsui.jsp?id=sfpwd", "http://mysite/bbsui.jsp?id=ds35e", "http://mysite/bbsui.jsp?id=124536" ); for ( @strings ) { my ($base, $id) = split( /=/, $_, 2 ); print "Id: $id\n"; }` [download] -- -- Ghodmode Blessed is he who has found his work; let him ask no other blessedness. -- Thomas Carlyle	[reply] [d/l] [select]
A reply falls below the community's threshold of quality. You may see it by logging in.
Re: i wann get some character from a string by planetscape (Chancellor) on Aug 02, 2006 at 17:53 UTC
FWIW, these are my most frequently used resources for constructing/understanding regexes: Mastering Regular Expressions perlrequick perlretut perlre YAPE::Regex::Explain GraphViz::Regex The Regex Coach (Win32 only, IIRC) HTH, planetscape	[reply]
Re: i wann get some character from a string by Lidskjalv (Novice) on Aug 02, 2006 at 18:51 UTC
My understanding is that you want ids as a comma separated list, for all ids used as the suffix to the one and only prefix as in $base below. I have added two strings to the collection in order to filter out strings of no interest to you. Try this code: `use strict; use warnings; my @strings = ( "http://mysite/bbsui.jsp?id=dxpwd", "http://mysite/bbsui.jsp?id=dxpsf", "http://mysite/bbsui.jsp?id=sfpwd", "http://somewhere.else.jsp?id=YOU-DO-NOT-WANT-THIS", "http://mysite/bbsui.jsp?id=ds35e", "http://somewhere.else.too?id=XXXXXXXXXXXXXXXXXXXX", "http://mysite/bbsui.jsp?id=124536" ); my $base = 'http://mysite/bbsui.jsp?id='; my $pattern = "^\Q$base\E(.+)\$"; my @id = grep { $_ } map { $1 if /$pattern/ } @strings; print "(" . join (',', @id) .")\n";` [download] Prints the requested output: `(dxpwd,dxpsf,sfpwd,ds35e,124536)` [download]	[reply] [d/l] [select]
Re^2: i wann get some character from a string by weihe (Initiate) on Aug 03, 2006 at 02:26 UTC
thanks very much	[reply]
Re: i wann get some character from a string by jesuashok (Curate) on Aug 02, 2006 at 03:24 UTC
Hi Is that ur home work ? update .. `use strict; use warnings; my @strings = ( "http://mysite/bbsui.jsp?id=dxpwd", "http://mysite/bbsui.jsp?id=dxpsf", "http://mysite/bbsui.jsp?id=sfpwd", "http://mysite/bbsui.jsp?id=ds35e", "http://mysite/bbsui.jsp?id=124536" ); for ( @strings ) { my ($id) = split( /=/, $_)[1]; print "Id: $id\n"; }` [download] or `$xyz = "http://mysite/bbsui.jsp?id=dxpwd"; $id = $1 if ($xyz =~ m/\?id=(.+?)$/i);` [download] "Keep pouring your ideas"	[reply] [d/l] [select]