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Re: perl file i/o
Guy is right , but it should be:
open FH, "+>>$file"
see
http://www.eprotect.com/stas/TULARC/webmaster/myfaq.html
#How do I modify my file by opening it only once:
I hope it will help you
If you want to read a realy nice perl stuff , read:
The WebTechniques Perl Columns- monthly column for Web Techniques magazine
(by Randal L. Schwartz )
http://www.stonehenge.com/merlyn/WebTechniques/
The Unix Review Perl Columns - bi-monthly column for Unix Review
magazine (by Randal L. Schwartz )
http://www.stonehenge.com/merlyn/UnixReview/
That's where I've learned about +>> stuff...
>
> On Sat, 6 Dec 1997, shahar shocron wrote:
>
> > open(FILE, "+<$file");
> > while(<FILE>);
> > {
> > &change_record;
> > print FILE $new_record;
> > }
> > close(FILE);
>
> 1. is the record you're writing of the exact same size as the record
> you're reading? if not, this method cannot work.
>
> 2. if the answer to '1' is 'yes', then after each read, you need to seek
> backwards in the file (using the perl 'seek' function) the ammount of
> characters you've read, and then you may write on top of that record.
>
> 3. if the answer to '1' is 'no', then you cannot write to the same file -
> create a temporary file, write everything to it, and after you've done
> and closed both files, rename the new file to the old file's name (this
> will also remove the old file from the system).
>
> 4. check the return value of any function call you make (open, close,
> print) to look for errors - if youll assume they always work, you'll
> get very buggy programms...
>
> this has nothing to do with perl - it has to do with any programming
> language.
>
> guy
>
>
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