> From: Raul Miller
> 
> On Tue, Aug 25, 2009 at 6:46 PM, Matthew
> Brand<[email protected]> wrote:
> > I have a 5GB text file with data which I want to process one line at
> a
> > time. Is there any way to stream through the file one line at a time
> > without reading in the whole thing and splitting it into lines? I
> > could break the file into smaller file and
> > proc...@split_into_lines@open them, but I wonder if there is an
> easier
> > way?
> 
> The way most languages implement this involves reading in
> blocks, finding line boundaries (lines will often span blocks)
> assembling lines and making them available one at a time
> to the program.
> 
> I do not know if anyone has bothered making this kind of
> facility for J, but J does support reading blocks.  See
> "Indexed Read" at http://www.jsoftware.com/help/dictionary/dx001.htm

See the verb freadblock and the adverb fapplylines in the files script.
open '~system/main/files.ijs'
open 'files'

See also this post/thread
http://www.jsoftware.com/pipermail/programming/2007-May/006694.html

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