How to make the filhandle to go back to the previos line

[sanjeeb]

hey
i want to make the filhandle to go back to the previousline.

snippet:

while(<ARGV>)
{
if($line mathes)
{
#do this
}
else
{
# Go back the handle to the previous line or may be multiple line
#
}
}


i want to make a wrapper function where the argument will be the "How
mnay lines to be back" and the handle.

I know we can do by using a buffer but i dont want to use becuase the
line number argument can be big.

Is there any one have solution.

Regards
sanjeeb

 

[Michele Dondi]

i want to make the filhandle to go back to the previousline.

use a buffer instead!

I know we can do by using a buffer but i dont want to use becuase the
line number argument can be big.

perldoc -f tell
perldoc -f seek

and so on...


Michele

 

[Tad McClellan]

i want to make the filhandle to go back to the previousline.

That depends on what the filehandle is connected to.

Some streams can be rewound and some can't.

i want to make a wrapper function where the argument will be the "How
mnay lines to be back" and the handle.

perldoc -f seek

perldoc -q filehandle

How can I make a filehandle local to a subroutine? How do I pass file-
handles between subroutines? How do I make an array of filehandles?

 

[Charles DeRykus]

hey
i want to make the filhandle to go back to the previousline.

snippet:

while(<ARGV>)
{
if($line mathes)
{
#do this
}
else
{
# Go back the handle to the previous line or may be multiple line
#
}
}


i want to make a wrapper function where the argument will be the "How
mnay lines to be back" and the handle.

I know we can do by using a buffer but i dont want to use becuase the
line number argument can be big.

You could build an array of line start positions with seek/tell which
would be fastest (perldoc `seek` and `tell`). But, if a simpler, slower
solution is acceptable, look at `Tie::File` which enables you to keep an
array of the file's lines. So, jumping to another line is just a reset
of the array index.