you will have an issue transferring any file using ssh2_scp_send unless you send a dummy file after your real file, or preferably issue an 

ssh2_exec ($connection, 'exit'); 

I was transferring hundreds of thousands of files in my prototype across multiple servers, and noticed that each file had a mismatched md5 hash and bytelength.

after a bit of research i learnt that this was a bug, and added the code above as suggested at pecl.php.net in the bugs section.

hopefully this helps someone who is getting partial file transfer that could ruin your whole app.

Installing on HPUX 11.11 cookbook

Just follow the install instructions on the man page and solved the problems as they appear

- when making libssh2
Problem related with /lib/pa20_64 and 64 bits library in 32 bits link
Edited the configure file  and changed
SHLIB_LDFLAGS="-b +vnocompatwarnings -L/lib/pa20_64"
to
SHLIB_LDFLAGS="-b +vnocompatwarnings -L/lib"

-when executing phpize
Problems with aclocal, autom4ke and m4
Installed automake, autoconf and m4

-when ./configuring the ssh2 
Configure: error: libssh2 version >= 0.4 not found
Edited the configure.m4 and removed the -ldl switch from line (as posted before)
39      -L$SSH2_DIR/lib -lm -ldl
runned phpize again and ./configure --with-ssh2

Getting strange "Unable to open ssh2.sftp://Resource id #3/example.txt" errors? This is a bug in PHP > 5.6.27. Use intval() as a workaround to make ssh2 work again:

$sftp = ssh2_sftp($connection);
fopen("ssh2.sftp://" . intval($sftp) . "/example.txt", 'r');

https://bugs.php.net/bug.php?id=73597

I was building out the ssh2 extension (0.10) under OpenBSD 3.9 on sparc64 and I got this error when running configure:

checking for libssh2_banner_set in -lssh2... no
configure: error: libssh2 version >= 0.4 not found

I did some poking around in the configure file and traced the problem down.  The reason for the failure is that configure is trying to compile a test program with -ldl.  libdl is not installed on OpenBSD 3.9. The OpenBSD folks purged libdl years ago and I could not find a package that contains it. 

(The error message above is misleading because the problem is not with libssh2.)

I looked at the ssh2 extension code and could not see a reason for using libdl, so I removed the -ldl from the config.m4 file.  Re-ran phpize and configure. No errors.  Did make and installed ssh2.so.  Works fine.

To list directory contents:

<?php
$connection = ssh2_connect(\"hostname\", 22);
ssh2_auth_password($connection,\"username\", \"password\");  // or use any of the ssh2_auth_* methods
$sftp = ssh2_sftp($connection);

$dh = opendir(\"ssh2.sftp://$sftp/path/to/dir/\");

while (($file = readdir($dh)) !== false) {
  echo \"$file is in hostname:/path/to/dir\\n\";
}

closedir($dh);
?>

(thanks to Sara for assisting)

Trying to compile this ssh PECL extension for Mac OS X (10.4.2) 
with entropy.ch's php5 distribution? Read on: PART 1:
1) Download libssh (I used version 0.11)
http://sourceforge.net/project/showfiles.php?group_id=125852
2) Unzip the directory and cd to the upacked directory in the terminal.
3) run: ./configure; make all install;
libssh should compile and place the output file in src/*.o
4) copy all headers from the include folder within the libssh2 directory to
/usr/local/include/
5) copy all compiled files (*.o) from the src folder within the libssh2 
directory to /usr/local/lib/
6) Download ssh2 
(I used version 0.9 with additional changes from cvs - explained below)
http://pecl.php.net/package/ssh2
7) unzip the downloaded archive.
8) version 0.9 has a conflict with an existing symbol used in some of the ZEND headers... 
a change is available in cvs which renames the symbol in ssh2 to avoid the conflict
http://cvs.php.net/diff.php/pecl/ssh2/ssh2.c?r1=1.9&r2=1.10&ty=h
down load at least the 1.10 version of ssh2.c
if you decide to download a newer version, download any of the corresponding related files, 
such as the php_ssh2.h header file.
9) replace the old version of ssh2.c with the new version of ssh2.c 
(and any other files you downloaded).
10) From the terminal: 
cd to the source directory (for me ssh2-0.9/ssh2-0.9/).

(Continued in a PART 2 comment)

Some installations of PHP 5 may have a problem starting the SSH2 extension as a Windows' service. It just started happening to me today, spontaneously. I have PHP 5.2.2 (and have tried 5.2.3), on Apache 2.0.59 .

It turns out that it's an Apache problem. Even though I was given an error message when starting it, it still worked perfectly from the CLI. So, I commented it out in the
INI file again, and am just loading it using extension_loaded('ssh2') and dl('php_ssh2.dll') from within the script.

Trying to compile this ssh PECL extension for Mac OS X (10.4.2) 
with entropy.ch's php5 distribution? Read on: PART 2:

11) Check your shell's path variable by SHELL$ "echo $PATH". 
If your php5 binary directory is not listed before the standard OS X binary directory, 
update your $PATH variable to list it first. Mine reads: 
/usr/local/mysql/bin/: /usr/local/php5/bin/: /bin:/sbin: /usr/bin:/usr/sbin 
11a) if you do not do this step, the PECL extension will link against the old 
php4 version that ships with Mac OS X. You will know this by the fact that the 
next step lists a server API that is different than the output of phpinfo(): 
My version was 20041030, Apples version was 20020429.
12) Run: phpize && ./configure --with-ssh2 && make
This will produce a lot of output and probably some warnings. If you get a note 
at the end that says "Build Complete", then the process has completed 
(probably successfully). The command has produced the output file ssh2.so within 
the ssh2-0.9 (or whatever version) directory.
13) Check where the extension directory is located at by running the following command:
SHELL$/usr/local/php5/bin/php-config --extension-dir
If it lists some directory that actually exists, copy the ssh2.so file to this directory.
If it doesn't list a location that exists, you can either create the location, or 
choose a different location and update the line in your php.ini file:
extension_dir = "./"
to point to the directory you would like to use. I chose:
extension_dir = "/usr/local/php5/extensions/"?>
14) Add the line
extension=ssh2.so
to the Dynamic Extensions area of your php.ini file.
15) Restart your web server for the extensioin to be loaded. If there are any problems, they will be written to the webserver log.
16) Check if your new ssh based streams are available by running:
SHELL$ /usr/local/php5/bin/php -r "print_r(stream_get_wrappers());"
You should get something similar to this output:
Array
(
    [0] => php
    [1] => file
    [2] => http
    [3] => ftp
    [4] => compress.bzip2
    [5] => compress.zlib
    [6] => https
    [7] => ftps
    [8] => ssh2.shell
    [9] => ssh2.exec
    [10] => ssh2.tunnel
    [11] => ssh2.scp
    [12] => ssh2.sftp
)
You should now be able to do all the cool things you need to do with ssh 
(like sftp scp ssh execution)! Take a look at some of the comment here for some 
example scripts to test things out:
http://us2.php.net/manual/en/ref.ssh2.php

Good luck... hope that saves you my headache! :)