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[REBOL] Re: Deleteing lines from a big file

From: holger:rebol at: 17-Jul-2001 9:51

On Mon, Jul 16, 2001 at 03:23:40PM -0700, Ken Vincent wrote:
> Greetings, > > I'm looking for a way to delete problematic lines from very large data files (too large for buffered access). > > row-to-delete: 25 > condition: "00000027" > > big-file: open/direct/lines %VeryBigDataFile.DAT > skip big-file (row-to-delete - 1) > line-to-check: first big-file ; confirm that this is the correct line to delete > if (find line-to-check condition) <> none [remove line] <------------- Is there some way to do this???
No, because operating systems do not allow this. File data is typically stored consecutively, so you cannot delete something in the middle of a file. The best solution is to copy the file to another file, line by line, in /direct mode, skipping the line you want to delete. Then delete the old file and rename the new one. -- Holger Kruse [holger--rebol--com]