Shell Programming and Scripting

Hi

I have a file from which i need to remove the first 4 and the last 2 lines.. i know how to do it with sed but i need to do it in a perl script.. can you please help me how to do that.

Thanks

You would use the Tie::File module. The Tie::File documentation should explain it.

Or you could read the file into an array and use an array slice to remove the lines:

open(FH,'file');
@array = <FH>;
close FH;
open(OUT,'>','file');
print OUT @array[4..$#array-2];
close OUT;

Thanks for the quick reply, i tried it but it dint work for me.. i can make my situation more clear... i need to copy the data from a file except for the first 4 and the last 2 lines to a new file .. say File1 has lines
a1
a2
a3
a4
a5
.
a59
a60
a61

my new file should contain
a5
..
a59

Hope im clear.. a quick solution is really appreciated... thanks

this should do eaxctly that:

open(FH,'file');
@array = <FH>;
close FH;
open(OUT,'>','outfile');
print OUT @array[4..$#array-2];
close OUT;

Might not work if the file is too big to fit into memory.

File size is 742B .. alrite i will try it one more time..
open(FH,'file'); #opens the file
@array = <FH>; # writes the file data into an array
close FH; #closes the file
open(OUT,'>','outfile'); #???? can u please tell me wats happening here
print OUT @array[4..$#array-2]; #???? and here toooo
close OUT; #?????

Thanks again for ur quick reply

1. open(OUT,'>','outfile'); #???? can u please tell me wats happening here
2. print OUT @array[4..$#array-2]; #???? and here toooo
3. close OUT; #?????

1. opens a new file for writing or opens an existing file for overwriting. Associates it with filehandle OUT.

2. prints the array minus the first 4 and last 2 elements to filehandle OUT, which in this case means the lines of the file. This is called an array slice: @array[n,n...n]. It would be the same as doing this:

shift @array;
shift @array;
shift @array
shift @array;
pop @array;
pop @array;

but the array slice will be much faster for what you are doing because it does not modify the array.

3. closes the file associated with IN filehandle.

That works... thanks a lot!! really appreciate it!