Gossamer Forum: General: Perl Programming: compare two text files

Jul 11, 2003, 6:42 PM

zeshan

User (98 posts)

Jul 11, 2003, 6:42 PM

Post #1 of 7

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compare two text files

list.txt (contains 3 enteries)
######
file1.html
file3.html
file2.html
######

data.txt (contains 2 enteries)
######
file3.html
file1.html
######

open (LIST, "list.txt");
@list = <LIST>;
chomp @list;
open (DATA, "data.txt");
@data = <DATA>;
chomp @data;
foreach $file (@list) {
foreach $line (@data) {
if ($file eq $line) {
print "$file exists\n";
}
}
}

############
It gives output:
file1.html exists
file3.html exists

My question how to Add file2.html DOESN't exist in the output.

The script is matching the files and reporting the files which exists, how can I get the files which are not matching?

TIA,

Zeshan.

Jul 12, 2003, 1:37 AM

Andy

Veteran / Moderator (18441 posts)

Jul 12, 2003, 1:37 AM

Post #2 of 7

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Re: [zeshan] compare two text files In reply to

Mmmm....how about something like;

Code:
# grab the data first. Stick it into a while  
# loop, so we don't slup too much memory up... 
open (LIST, "list.txt") || die "Cannot open list.txt. Reason: $!"; 
  while (<LIST>)  { 

    # now lets open the data.txt file, and we can  
    # put this one into an array... 
    open (DATA, "data.txt") || die "Cannot open file. Reason: $!"; 
      @data = <DATA>; 
    close(DATA); 

    # set to 0, so we have a false value to start with.. 
     $found = 0; 

   # go through each line in the array. If we have a 
   # match, skip to the end of the 'foreach', and  
   # define $found as 1... 
    foreach $line (@data) { 

      chomp $line; 
      if ($line eq $_) { $found = 1; last; } 
      $found = 0; # set to 0, cos it won't have been  
                        # found if we get this far... 

    } 

    if ($found) {  
       print "Entry \"$_\" was found in  data.txt <BR>";  
    } else {  
       print "Entry \"$_\" was NOT found in data.txt <BR>";  
    } 

  }

This is untested...so its not guarantteed to work. I'm hoping it will just give you the idea.

Cheers

Andy (mod)
andy@ultranerds.co.uk

Jul 12, 2003, 3:00 AM

Paul

Veteran (19537 posts)

Jul 12, 2003, 3:00 AM

Post #3 of 7

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Re: [Andy] compare two text files In reply to

Ewwwwwwwwwwwww

Why are you opening the second file on *every* iteration?

You only need to open it once to compare it to the other file.

Jul 12, 2003, 3:12 AM

Andy

Veteran / Moderator (18441 posts)

Jul 12, 2003, 3:12 AM

Post #4 of 7

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Re: [Paul] compare two text files In reply to

Mmm...goood point Tongue

Something like this then;

Code:
# now lets open the data.txt file, and we can   
 # put this one into an array...  
 open (DATA, "data.txt") || die "Cannot open file. Reason: $!";  
   @data = <DATA>;  
 close(DATA);  

# grab the data first. Stick it into a while   
# loop, so we don't slup too much memory up...  
open (LIST, "list.txt") || die "Cannot open list.txt. Reason: $!";  
  while (<LIST>)  {  

    # set to 0, so we have a false value to start with..  
     $found = 0;  

   # go through each line in the array. If we have a  
   # match, skip to the end of the 'foreach', and   
   # define $found as 1...  
    foreach $line (@data) {  

      chomp $line;  
      if ($line eq $_) { $found = 1; last; }  
      $found = 0; # set to 0, cos it won't have been   
                        # found if we get this far...  

    }  

    if ($found) {   
       print "Entry \"$_\" was found in  data.txt <BR>";   
    } else {   
       print "Entry \"$_\" was NOT found in data.txt <BR>";   
    }  

  }

Cheers

Andy (mod)
andy@ultranerds.co.uk

Jul 12, 2003, 2:43 PM

zeshan

User (98 posts)

Jul 12, 2003, 2:43 PM

Post #5 of 7

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Re: [Andy] compare two text files In reply to

Not Working for the above given 2 text files (see the top lines), its producing the output...

Entry "file1.html " was NOT found in data.txt
Entry "file3.html " was NOT found in data.txt
Entry "file2.html " was NOT found in data.txt

though, file1.html and file2.html exists in data.txt

any help?

######################

open (DATA, "data.txt") || die "Cannot open file. Reason: $!";
@data = <DATA>;
close(DATA);

open (LIST, "list.txt") || die "Cannot open list.txt. Reason: $!";
while (<LIST>) {
$found = 0;

foreach $line (@data) {
chomp $line;
if ($line eq $_) { $found = 1; last; }
$found = 0;
}

if ($found) {
print "Entry \"$_\" was found in data.txt <BR>";
}
else
{
print "Entry \"$_\" was NOT found in data.txt <BR>";
}
}

#####################

Thanks,

Zeshan.

Jul 13, 2003, 2:27 AM

Andy

Veteran / Moderator (18441 posts)

Jul 13, 2003, 2:27 AM

Post #6 of 7

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Re: [zeshan] compare two text files In reply to

Please attach all 3 files (the two .txt file, and the .cgi). I'll have a play around with it, and see what it does.

Cheers

Andy (mod)
andy@ultranerds.co.uk

Jul 13, 2003, 1:12 PM

zeshan

User (98 posts)

Jul 13, 2003, 1:12 PM

Post #7 of 7

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Re: [Andy] compare two text files In reply to

You were chomping the list.txt but not the data.txt, due to which it was giving error.

I fixed it.

Once again I appreciate your help.

Zeshan.