Net::SSH2::File - SSH2 SFTP file object
An SFTP file object is created by the Net::SSH2::SFTP
Read size bytes from the file into a given buffer. Returns number of bytes read, or undef on failure.
Write buffer to the remote file.
libssh2_sftp_write function wrapped by this method has a complex and quite difficult (if not impossible at all) to use API.
It tries to hide the packet pipelining being done under the hood in order to attain decent throughput.
Net::SSH2 can not hide that complexity without negatively affecting the transmission speed so it provides just a thin wrapper for that library function.
An excerpt from
libssh2_sftp_write manual page follows:
WRITE AHEAD Starting in libssh2 version 1.2.8, the default behavior of libssh2 is to create several smaller outgoing packets for all data you pass to this function and it will return a positive number as soon as the first packet is acknowledged from the server. This has the effect that sometimes more data has been sent off but isn't acked yet when this function returns, and when this function is subsequently called again to write more data, libssh2 will immediately figure out that the data is already received remotely. In most normal situation this should not cause any problems, but it should be noted that if you've once called libssh2_sftp_write() with data and it returns short, you MUST still assume that the rest of the data might've been cached so you need to make sure you don't alter that data and think that the version you have in your next function invoke will be detected or used. The reason for this funny behavior is that SFTP can only send 32K data in each packet and it gets all packets acked individually. This means we cannot use a simple serial approach if we want to reach high performance even on high latency connections. And we want that.
Returns file attributes; see Net::SSH2::SFTP::stat.
Sets file attributes; see Net::SSH2::SFTP::setstat.
Set the file pointer offset.
Returns the current file pointer offset.
Copyright (C) 2005, 2006 by David B. Robins <firstname.lastname@example.org>;
Copyright (C) 2015 by Salvador Fandiño <email@example.com>;
All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.0 or, at your option, any later version of Perl 5 you may have available.
The documentation for this package contains and excerpt from libssh2 manual pages. You can consult the license of the libssh2 project for the conditions regulating the copyright of that part.