Assuming your file isn't too big (i.e will comfortably fit in memory) 
open(my $fh, "<+", "your_file") or die("ack: $!");
my @data = <$fh>;
seek $fh, 0, 0;

my $newsize = 0;
for(@data) {
  next unless /\bsome string\b/;
  print $fh;
  $newsize += length;
}

truncate $fh, $newsize;
close $fh;

[download]
Or if the file is too big to be read entirely into memory 
open(my $read,  "<", "your_file") or die("ack: $!");
open(my $write, ">", "tmpfile$$") or die("ack: $!");

while(<$read>) {
  next unless /\b some string\b/;
  print $write;
}

close $read;
close $write;

rename $write, $read;

[download]
See. perlopentut and perlfunc for more info.
HTH

_________
broquaint

In reply to Re: Re: Re: delete a line by a string by broquaint
in thread delete a line by a string by moked

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