Saravana Kumar wrote:
> Hi,
Hello,
> I am new to the list and newbie in perl.
>
> I have a big flat file(100G). The file was supposed to be in a single line
> but many of records(as it has ^M). There are also ^@ and tabs in between.
>
> I want to first replace the control characters and tabs with space.
>
> I tried this s/[[:cntrl:]\t]/ /g.
The [:cntrl:] character class includes the "\t" character.
> After replacing the above said characters
> with space i have to insert \n after each 1000th character.
>
> But the program hangs after reading about 24G( 1/4th of the file).
>
> I thought of reading the file character by character, check if the character
> is ^M||^@||\t. If true replace with the space and write the ouput else
> simply write the output. I have to keep track of the count of characters
> so as to insert \n after each 1000th character.
>
> Will the above work or is there any other(simple) way to do this?( or should
> i just move on to C?)
>
> I am not sure why my first program hang(i ran the program in a machine with
> 2G RAM).
You can do what you want if you set the Input Record Separator to read 1000
bytes at a time:
$/ = \1000;
while ( <FILE> ) {
s/[[:cntrl:]]/ /g;
print "$_\n";
}
John
--
use Perl;
program
fulfillment
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