Use Net::FTP to get a file and parse it without saving the file locally

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

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Re: Use Net::FTP to get a file and parse it without saving the file locally by petral (Curate) on Oct 27, 2001 at 03:47 UTC
If you look into the `get` routine in FTP.pm, you'll see that it's reading a buffer, then writing it to the passed-in filehandle. If you just want to hack on it, make your own copy and save the buffer in the ftp object and return that. Or, to be closer to "production", inherit FTP into a wrapper object and override get(). In the end, it's probably easier to write to a temporary file and parse that. The time to write and read the local file will almost certainly be a tiny fraction of the ftp connect and transmit time. (update) If you really want to get into it, you could look at Net::FTPServer. That lets you write your own site commands. You could do "`SITE PARSE filename`" and let the server parse the file and send back a 200 response with the needed data. Now, that* would be an efficiency! p	[reply] [d/l] [select]
Re: Use Net::FTP to get a file and parse it without saving the file locally by runrig (Abbot) on Oct 27, 2001 at 02:40 UTC
You can use IO::Scalar and pass Net::FTP the filehandle, or use IO::File's new_tmpfile() to create a file handle and pass it to Net::FTP. Update: I looked at the link in AnonyMonk's reply, then I looked at the code. With a little patching, there doesn't seem to be any real need to use fileno, unless Mr. Barr knows of a good reason not to go this route (I don't have anything to test on at the moment, so it'll have to wait if I try to do it) :-) Update: I think princepawn has a better idea anyway :)	[reply]
Re: Re: Use Net::FTP to get a file and parse it without saving the file locally by Anonymous Monk on Oct 27, 2001 at 02:54 UTC
You can use IO::Scalar and pass Net::FTP the filehandle Probably not. Net::FTP uses fileno to get the file descriptor for the passed filehandle and an IO::Scalar won't have a file descriptor. More detail here	[reply]
Use an anonymous tmp file by Fletch (Bishop) on Oct 27, 2001 at 20:02 UTC
If you're on a POSIX-ish OS you can always open a temporary file read/write and then immediately `unlink` it to remove it from the filesystem. As long as you still have a file descriptor for it you can manipulate it any way you want. Pass it to Net::FTP, use `seek` to rewind back to the beginning, then read the contents. As soon as you `close` the handle the underlying storage on disk will go away for good.	[reply]
Re: Use Net::FTP to get a file and parse it without saving the file locally by princepawn (Parson) on Oct 27, 2001 at 02:44 UTC
I think you are answering the opposite question, Doug :-)... He probably wants the `RETR`method to return a filehandle from the remote FTP server and then he wants to a $filehandle->getline to read from it.	[reply] [d/l]
Re: Use Net::FTP to get a file and parse it without saving the file locally by gbarr (Monk) on Oct 30, 2001 at 02:26 UTC
If you want to read a file directly into your process and not save it to a file then call `$ftp->retr` instead of `$ftp->get` This will return you a file handle that you can read from just like any other.	[reply] [d/l] [select]