I usually use a script from the Perl Cookbook (first edition) when I need to randomize the lines in a file. It works great. The script loads the entire file into memory as an array, then uses a fischer-yates shuffle to randomize the array elements before printing them out.
But this time, my file is much larger and I'm wondering if there is a better method to use. The file has around 3.7 million entries, and is 227 megabytes in size. My machine has 512MB of memory, but I was afraid this was going to bring it to its knees. And in fact, when I tried, it quickly died with an "out of memory" error. Is there a better way to randomize the lines in a file, that works for files that would challenge the memory capacity of a machine? I can do the coding; I'm just wondering about what approaches people would suggest.
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
Outside of code tags, you may need to use entities for some characters:
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||