[RLUG] quick question

[Anna]

oh, woops.  hehe.  Missed that part.  sorry.

another way of doing it with C might be with mmap() and memmove().  I
know this doesn't add much to the conversation.  I'm just curious about
how well it would work.

- Anna


On Wed, Jun 28, 2006 at 05:37:04PM -0700, James Washer wrote:
> But that is NOT "in place"... i.e. when finished, he'll have two copies of the file. If disk space is tight... that won't work.
> 
> On Wed, 28 Jun 2006 17:22:18 -0700
> Anna <christiana at hipointcoffee.com> wrote:
> 
> > find out which byte terminates the first 300 lines.  maybe...
> > 
> > ~$ BYTES=$(head -300 nameofbigfile.txt | wc -c)
> > 
> > then use that info with dd skip the first part of the input file...
> > 
> > ~$ dd if=nameofbigfile.txt of=truncatedversion.pl ibs=$BYTES  skip=1
> > 
> > one of many ways, I'm sure.  I think this way should be pretty fast
> > because it works on a line by line basis for just a small part of the
> > file.  The rest, with dd, is done in larger pieces.
> > 
> > - Anna
> > 
> > 
> > On Wed, Jun 28, 2006 at 01:01:03PM -0700, Grant Kelly wrote:
> > > Alright unix fans, who can answer this the best?
> > > 
> > > I have a text file, it's about 2.3 GB. I need to delete the first 300
> > > lines, and I don't want to have to load the entire thing into an
> > > editor.
> > > 
> > > I'm trying `sed '1,300d' inputfile > output file`  but it's taking a
> > > long time (and space) to output everything to the new file.
> > > 
> > > There has got to be a better way, a way that can do this in-place...
> > > 
> > > 
> > > Grant
> > > 
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