Shell Programming and Scripting

In a 10-50GB file , at end of file there is Control-z character
tried the below options,
1. perl -p -i -e 's/^Z//g' new.txt
2. perl -0777lwi -032e0 new.txt
and Sed command, dos2unix etc

it takes more time to remove the control-z. need a command or perl program to GO TO LAST LINE OF FILE DIRECTLY AND REMOVE CTRL-Z CHARACTER . we need tat to be removed in less than a second.

it takes in minutes to remove the control-z in 1GB file.
Please help asap. Thanks in advance.

If it's the last byte in the file, just use the truncate system call. Perl provides a wrapper for it. http://perldoc.perl.org/functions/truncate.html.

Regards,
Alister

Can anyone give the entire code(using truncate) to achieve this please.
If any other solution also please let me know thanks.

try this

Code:

 
perl -i -pe '$_=~s/^Z// if eof' filename

See

Code:

perldoc -f truncate

Be careful, it may destroy your file:

Code:

dd bs=filesize-1 seek=1 if=/dev/null of=file

Code:

#!/usr/bin/perl
use strict;
my $abs;
open(FILE ,"tt.txt");
seek(FILE,-2,2);
read(FILE,$abs,1);
print $abs;
$abs=~s/^Z//g;
print FILE "$abs";
print $abs;
close(FILE);

I want to directly go to end of the file (without reading whole big file)
and remove the ctrl-Z character and write back to file.
No need of one-liners(since it works but takes long time for big file)
Update me please