Is this the most efficient way to get and remove first line in file?

Question

I have a script which, each time is called, gets the first line of a file. Each line is known to be exactly of the same length (32 alphanumeric chars) and terminates with \"

Answer 1

I wouldn't usually recommend opening up a shell for this sort of thing, but if you're doing this infrequently on really large files, there's probably something to be said for:

$lines = `wc -l myfile` - 1;
`tail -n $lines myfile > newfile`;

It's simple, and it doesn't involve reading the whole file into memory.

I wouldn't recommend this for small files, or extremely frequent use though. The overhead's too high.