I'm thinking I don't want to slurp the whole file into an array or a hash and then somehow sort that.

If you don't want to pull the whole file into memory, you have a several alternatives. Here are two:

  1. Pull pieces of the file into memory, sort them, and write them to temporary files. Then merge the results into a final, sorted file.

  2. Scan the file once, remembering the seek offset of the beginning of each record, and the key you want to sort on. Sort the {key, offset} pairs, and then use this sorted list to seek/read records, emitting them in sorted order into a new file.

If you have enough memory to deal with the {key, offset} pairs, I'd go that way. It's easier to code. The descriptions of tell() and seek() in perlfunc tell you what you need.

In reply to Re: Sorting A File Of Large Records by dws
in thread Sorting A File Of Large Records by Anonymous Monk

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