Parsing a file

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

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Re: Parsing a file by broquaint (Abbot) on Jan 22, 2004 at 17:58 UTC
You're reading the file twice `while(<FILE>) { ## assign $_ to readline FILE my $message = <FILE>; ## assign my $message to readline FILE` [download] Which is one problem, and another is you're using the regex anchor `\A` which matches the beginning of a string. So you're matching `berta226:` to the beginning of the string, which will also make the regex fail. If you change your code to something like this you should get the desired output (updated - dropped extraneous semi-colon on second line. update 2: also fixed a further 2 mistakes as noted below .oO(note to self - don't post in a hurry shortly before leaving ... )) `while(my $message = <FILE>) { print "$1: $2<br/>" if $message =~ /^(Alberta226: )([a-zA-Z, 0-9]+)/; # I added the + }` [download] See. `perlsyn` and `perlre` for more info. HTH `_________ broquaint`	[reply] [d/l] [select]
Re: Re: Parsing a file by sulfericacid (Deacon) on Jan 23, 2004 at 07:35 UTC
I know I'm not the smartest person here or even really all that great with regexes, but shouldn't the + be inside the ()'s like `([a-zA-Z, 0-9]+)`? Otherwise it'll only trap the first character in the rexex. "Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us" sulfericacid	[reply] [d/l]
Re: Re: Parsing a file by Anonymous Monk on Jan 22, 2004 at 19:20 UTC
I tried your snippet but it keeps erroring out on if /^.., do you have any idea why?	[reply]
Re: Re: Re: Parsing a file by ysth (Canon) on Jan 22, 2004 at 19:38 UTC
I think the line before the `if` wasn't supposed to have a semi-colon (`;`) at the end.	[reply] [d/l] [select]
Re: Re: Parsing a file by Anonymous Monk on Jan 22, 2004 at 20:16 UTC
This is so weird. I rid of the colon and it doesn't crash, but it doesn't print or find anything. An exact copy of my log file is `Paltalk: This is a G rated voice group intended for a General Audience + including minors. Offensive language is not permitted. To speak, h +old the ctrl key down. ladymindy: gu ladymindy: jo ladymindy: hi pixelatedcyberdust: hi Alberta226: ((((( LM )))))) ladymindy: ((((((much)))))) ladymindy: i can t read ladymindy: (((((((alkberta)()))))) eartistp: hey pixels awake too eartistp: can't type either today lol pixelatedcyberdust: yep, very awake Alberta226: much is here ???` [download]	[reply] [d/l]
Re^3: Parsing a file by Nkuvu (Priest) on Jan 22, 2004 at 20:27 UTC
If you're using this code: `while(my $message = <FILE>) { print "$1: $2<br/>" if /^(Alberta226: )([a-zA-Z, 0-9])+/; # I added the + }` [download] you'll need to fix one little thing. The lines from `FILE` are being assigned to `$message` but the regex is matching against `$_` So you could do this as `while(<FILE>) { print "$1: $2<br/>" if /^(Alberta226: )([a-zA-Z, 0-9])+/; }` [download] or `while(my $message = <FILE>) { print "$1: $2<br/>" if $message =~/^(Alberta226: )([a-zA-Z, 0-9])+/; }` [download]	[reply] [d/l] [select]
Re: Parsing a file by allolex (Curate) on Jan 22, 2004 at 18:07 UTC
You're not quite there with filehandles, yet. First you are telling Perl to get each line (actually record) in a file, one at a time, using while. Then you're making a reference to that same filehandle again while the line you want is already in the special variable $_. Try this (untested) code: `print header, start_html('log parsing'); open(FILE, "<", 'log.txt') or die "Cannot open file: $!"; while (<FILE>) { # $_ is your message, but you could also # say "while my $message ..." to store # each line in $message chomp; # gets rid of newlines, etc. if ( m/(^Alberta226:)\s+(.*)/ ) { # you just need # the one anchor print "$1: $2<br>\n"; # add a newline for HTML output legibility } } close (FILE) or die "Cannot close file: $!";` [download] -- Allolex	[reply] [d/l]