On Tue, 3 Feb 2004 11:06:08 -0300
"Marcelo" <[EMAIL PROTECTED]> wrote:
> Hi everyone, need help with two things;
>
> how do you find out if a line is duplicated in a file, and delete it if so.
>
> how do you delete a line if it has more than x number of characters.
You probably need to define your problem a bit better
How large is the file
What order is it, and does it have to keep that order
Are the duplicate lines sequential or randomly placed
perldoc -q duplicates
perldoc -f length
is initial documentation to read.
The simple process for sequential duplicates is
open the file for reading
open a file for writing
read the file line by line
test if the line read is the same as the last line read
if it is, read the next line, otherwise write the line to file
test if the line has more than x characters
if it is go to the next line, otherwise write to the file
when finished, unlink the initial file
then rename your write file to your read file name.
here is a simple example, printing to stdout
#!/usr/bin/perl -w
while (<DATA>){
next if (length($_)>20);
next if defined $previous and $previous eq $_;
print;
$previous = $_;
}
__DATA__
This is a line
This is a line
This is a line
This is not a line
This is a line This is a line This is a line
This is a line also
--
Owen
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