Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister
 
PerlMonks  

Re^2: Temp file strategy

by chb (Deacon)
on Sep 19, 2005 at 06:55 UTC ( #493092=note: print w/replies, xml ) Need Help??


in reply to Re: Temp file strategy
in thread Temp file strategy

This is an interesting feature, but how can a user download such a file? If I understand perldoc -f open correctly, this syntax gives you a filehandle to an anonymous temporary file. Will you need some sort of streaming or some webserver trickery to let the user access this file from outside the perl script?

Replies are listed 'Best First'.
Re^3: Temp file strategy
by blazar (Canon) on Sep 19, 2005 at 09:59 UTC
    Indeed. But it depends on the OS you're under: I'm not really sure, but I think that Windows doesn't support real anonymous files, so the temporary file that you can see should still be there somewhere.

    Here I'm under Linux and I get

    $ strace -e open perl -e 'open $f, "+>", undef' 2>&1 | tail -n 1 open("/tmp/PerlIO_vfNALU", O_RDWR|O_CREAT|O_EXCL|O_LARGEFILE, 0600) = +3
    but of course it is soon deleted:
    $ perl -le 'open $f, "+>", undef; print readlink "/proc/self/fd/" . fileno $f' /tmp/PerlIO_vJg2Uf (deleted)
    (or
    $ perl -le 'open $f, "+>", undef; print readlink "/proc/self/fd/" . fileno $f' /tmp/.nfs0004821b00000353
    if run on a machine where /tmp is mounted under nfs.)

    Whatever, all this is at best fragile and tricky. This interesting open feature is best suited for a file to write stuff into, to recover it later. For your application any of the other suggestions you got would be probably preferable.

    I just mentioned this temp file strategy option because IMHO it would deserve to be better known.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://493092]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chilling in the Monastery: (4)
As of 2019-10-19 06:24 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Notices?