note 95301 added to function.ssh2-exec

ssh2_exec() is buggy as all get out. As posts below this one have noted, it frequently only returns a portion of the desired output and that's assuming it returns anything at all. sleep() often fixes this but using sleep() in a for loop is a bad idea. jaimie at seoegghead dot com suggests using a "sentinel character" but not even that's fool proof. Try, for example, to cat an arbitrary file - can you guarantee that the "sentinel character" won't appear in the output? He also suggests that you can "escape the output via some encoding mechanism" but that doesn't work, either. Besides, how does he propose that be done, anyway? Maybe cat filename.ext | urlencode? I have no clue but that shouldn't be necessary, anyway. phpseclib (http://phpseclib.sourceforge.net/) - a pure-PHP implementation of SSH - makes this a non-issue as it returns all the output all the time. The reason the ssh2 PECL extension doesn't is because uses channels of type 'shell' and not of type 'exec'. With 'exec', you read from the channel until the channel is closed. With 'shell', the channel is never closed by the server and as such you have no way of knowing how much reading needs to be done. Also, 'shell' is just more time consuming then 'exec' - in my experience, it's as though 'shell' tries to throttle the output so it doesn't display too fast. That may be nice in an interactive shell but in a library it's not at all desirable. ---- Server IP: 192.41.40.227 Probable Submitter: 66.68.45.157 ---- Manual Page -- http://www.php.net/manual/en/function.ssh2-exec.php Edit -- https://master.php.net/note/edit/95301 Del: integrated -- https://master.php.net/note/delete/95301/integrated Del: useless -- https://master.php.net/note/delete/95301/useless Del: bad code -- https://master.php.net/note/delete/95301/bad+code Del: spam -- https://master.php.net/note/delete/95301/spam Del: non-english -- https://master.php.net/note/delete/95301/non-english Del: in docs -- https://master.php.net/note/delete/95301/in+docs Del: other reasons-- https://master.php.net/note/delete/95301 Reject -- https://master.php.net/note/reject/95301 Search -- https://master.php.net/manage/user-notes.php