retrieve filename from filehandle?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: retrieve filename from filehandle? by zentara (Cardinal) on Jan 16, 2006 at 12:57 UTC
What if the filehandle is a pipe, socket, or opened to a scalar, etc? I don't think there is anything that is simple and cross-platform Perl. But why would you need this? If you opened the filehandle with your script, you ought to know where it's coming from or going to. :-) You can get the file descriptor for the filehandle. Read "perldoc -f fileno" `perldoc -f fileno fileno FILEHANDLE Returns the file descriptor for a filehandle, or undefined if the filehandle is not open.` [download] I'm not really a human, but I play one on earth. flash japh	[reply] [d/l]
Re: retrieve filename from filehandle? by blazar (Canon) on Jan 16, 2006 at 13:33 UTC
zentara told you how to get the file descriptor of your handle. Now, under Linux you can get a symlink to your original file from `/proc/self/fd/$descriptor` [download] I don't know how portable this is to other unices, not to say osen - generally I expect little to zero. Still it may be suitable for you!	[reply] [d/l]
Re^2: retrieve filename from filehandle? by tirwhan (Abbot) on Jan 16, 2006 at 19:35 UTC
A slightly more cross-platform way of doing this (works on most Unixes) would be to use `lsof`. The following will first determine the file descriptor from the filehandle (as per zentara's example) and then uses this file descriptor to find the file name. my $desc = fileno($handle); my $name = (`lsof -Fn -a -d $desc -p $$`)[1]; $name = substr($name,1); [download] There are ten types of people: those that understand binary and those that don't.	[reply] [d/l] [select]
Re^2: retrieve filename from filehandle? by Arunbear (Prior) on Aug 09, 2007 at 09:16 UTC
Thank you very much for that tip! Here is an example of how it could be used: arun@butterfly:~> perl -de 0 Loading DB routines from perl5db.pl version 1.23 Editor support available. Enter h or `h h' for help, or `man perldebug' for more help. main::(-e:1): 0 DB<1> open $fh, '>', 'temp.txt' DB<2> x $fh 0 GLOB(0x816b940) -> main::$fh FileHandle({main::$fh}) => fileno(6) DB<3> $d = fileno $fh DB<4> p $d 6 DB<5> p qx[ls /proc/$$/fd] 0 1 2 3 4 5 6 7 DB<6> p readlink("/proc/$$/fd/$d") /home/arun/temp.txt [download]	[reply] [d/l]