Re: Re: Regular Expression Problem

Here is what I consturcted from your example. However, it only returns the first line where there is a creat table statment. I get nothing like what you got. Could you please take a look and let me know where I went wrong.
Thanks, Bobby

#!/usr/bin/perl -w
use strict;

my $file = "go.txt";

print "\nOpening $file\n";

open(FILE, "< $file") || die "OLD FILE ERROR: Unable to open file: $!\
+n";
open(OUT, "> $file.new") || die"NEW FILE ERROR: Unable to create new f
+ile: $!\n";



while (<FILE>)
{
    my $data = join('', <FILE>);
    
    $data =~ s/(CREATE TABLE "SO"\.")([^"]+)(.+)(PRIMARY KEY)/$1 $2 $3
+ CONSTRAINT PK_$2 $4/ms;

    print OUT;    
}


print "Closing $file\n";

close(OUT) || die "Unable to close OUT file: $!\n";
close(FILE) || die "Unable to close OLD file: $!\n";
[download]

Comment on Re: Re: Regular Expression Problem Download Code

Replies are listed 'Best First'.
Re: Re: Re: Regular Expression Problem by dakkar (Hermit) on Nov 26, 2002 at 21:26 UTC
First, a note: the `join` operator is already reading the whole file into memory (the `<FILE>` is evaluated in list context, so it returns all the lines from the file), so there is no need for the `while` loop. You should just say: `#!/usr/bin/perl -w use strict; my $file = "go.txt"; print "\nOpening $file\n"; open(FILE, "< $file") \|\| die "OLD FILE ERROR: Unable to open file: $!\ +n"; open(OUT, "> $file.new") \|\| die"NEW FILE ERROR: Unable to create new f +ile: $!\n"; my $data=join('',<FILE>);` [download] Anyway, there is an error in the regexp, and one in the modifiers. The line should be: `$data =~ s/(CREATE TABLE "SO"\.")([^"]+)(.+?)(PRIMARY KEY)/$1$2$3CONSTRAINT PK_$2 $4/msg;` I changed two things: I changed from `(.+)` to `(.+?)`, so that it matches the shortest string. Otherwise, when there are more than one "CREATE TABLE" in the file, it would match the first "CREATE" with the last "PRIMARY KEY". I added the `g` modifier, so that every match will be changed. And, of course, then you have to print the result: `print OUT $data; print "Closing $file\n"; close(OUT) \|\| die "Unable to close OUT file: $!\n"; close(FILE) \|\| die "Unable to close OLD file: $!\n";` [download] -- dakkar - Mobilis in mobile	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Re: Re: Regular Expression Problem
by dakkar (Hermit) on Nov 26, 2002 at 21:26 UTC

First, a note: the join operator is already reading the whole file into memory (the <FILE> is evaluated in list context, so it returns all the lines from the file), so there is no need for the while loop. You should just say:

#!/usr/bin/perl -w
use strict;

my $file = "go.txt";

print "\nOpening $file\n";

open(FILE, "< $file") || die "OLD FILE ERROR: Unable to open file: $!\
+n";
open(OUT, "> $file.new") || die"NEW FILE ERROR: Unable to create new f
+ile: $!\n";

my $data=join('',<FILE>);
[download]

Anyway, there is an error in the regexp, and one in the modifiers. The line should be:

$data =~ s/(CREATE TABLE "SO"\.")([^"]+)(.+?)(PRIMARY KEY)/$1$2$3CONSTRAINT PK_$2 $4/msg;

I changed two things:

I changed from (.+) to (.+?), so that it matches the shortest string. Otherwise, when there are more than one "CREATE TABLE" in the file, it would match the first "CREATE" with the last "PRIMARY KEY".
I added the g modifier, so that every match will be changed.

And, of course, then you have to print the result:

print OUT $data;

print "Closing $file\n";

close(OUT) || die "Unable to close OUT file: $!\n";
close(FILE) || die "Unable to close OLD file: $!\n";
[download]

-- 
        dakkar - Mobilis in mobile

[reply]
[d/l]
[select]