November 19, 2008 01:10am pst

02.23.2007 at 11:41AM PST, ID: 22409887

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7.6

What is the most efficient method to insert a line at the top of a file?

Asked by timdr in Perl Programming Language

Tags: insert, file, line, efficient, method

Hello all,

I need to insert a line of text at the top of a large text file (100+ MB) as part of a backup process. Many instances of this process may be running at the same time, so I need it to run as efficiently as possible.

I have been using Tie::File to do the prepend, like so:

# --------------------------------------------
my @fileArray;
tie @fileArray, 'Tie::File', $file or die '$!';

unshift @fileArray, $line;

untie @fileArray;
# --------------------------------------------

Running this code on a 100+ MB file takes ~4 seconds. I am hoping there is a method I don't know about which can make it almost as efficient as a simple append, which takes a mere half-second.

Thanks in advance for your help.Start Free Trial

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What is the most efficient method to insert a line at the top of a file?

Asked by timdr in Perl Programming Language

Tags: insert, file, line, efficient, method

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