>>On Tue, 31 Jul 2007, Thomas Harding wrote: >Daniel Stenberg <[EMAIL PROTECTED]> > >>My problem is that while using libssh2_channel_read_stderr, it seems to >>wait infinitely for data when no data is available, whatever channel is or >>is not in blocking mode. > >Can you please provide a complete small source snippet that reproduces the >problem?
Well, maybe the better will be to me to write such this, but it is not done... hope following code will be enough explicit. Complete source code: http://tom.harding.free.fr/vrac/python-ssh2.tgz edit and run files in test dir ################### # read_stderr function ################### static PyObject * SSH2_Channel_readstderr(SSH2_ChannelObj *self, PyObject *args) { int bufsiz, ret=0; //~ unsigned char *buf[1024]; PyObject *buf; if (!PyArg_ParseTuple(args, "i:read", &bufsiz)) return NULL; buf = PyString_FromStringAndSize(NULL, bufsiz); if (buf == NULL) return NULL; if (libssh2_channel_eof(self->channel)!=1) { MY_BEGIN_ALLOW_THREADS(self->tstate); ret = libssh2_channel_read_stderr(self->channel, PyString_AsString(buf), bufsiz); MY_END_ALLOW_THREADS(self->tstate); if (ret > 0) { if (ret != bufsiz && _PyString_Resize(&buf, ret) < 0) { return NULL; } return buf; } } Py_DECREF(buf); Py_INCREF(Py_None); return Py_None; } ###################### # # Popen function ##################### static PyObject * SSH2_Session_popen(SSH2_SessionObj *self, PyObject *args) { LIBSSH2_CHANNEL *channel; char *command; if (!PyArg_ParseTuple(args, "s:popen", &command)) return NULL; channel = libssh2_channel_open_session(self->session); if (channel == NULL) { PyErr_SetString(PySSH2_Error, "SSH error."); return NULL; } if (libssh2_channel_exec(channel, command)) { PyErr_SetString(PySSH2_Error, "Unable to request command execution on remote host"); libssh2_channel_free(channel); } return (PyObject *)(SSH2_Channel_New(channel, 1)); } ################# Python code ################# def testPopenBlocking(self): ssh = SSH2.Session() ssh.setBanner(SSH2.DEFAULT_BANNER) ssh.startup(self.getConnexion()) ssh.setPassword(LOGIN, PWD) channel = ssh.popen(command) print channel if channel: channel.setBlocking(True) while 1: if channel.eof(): print "EOF" break data = channel.read(BUFFER) if data: sys.stdout.write(data) errors = None errors = channel.readstderr(BUFFER) if errors: sys.stderr.write(errors) if channel.eof(): print "EOF" break ssh.close() def testPopenNonBlocking(self): print "#########################" print "#" print "# test Popen Non Blocking" print "#" print "#########################" time.sleep(2) ssh = SSH2.Session() ssh.setBanner(SSH2.DEFAULT_BANNER) ssh.startup(self.getConnexion()) ssh.setPassword(LOGIN, PWD) channel = ssh.popen(command) print channel l = 0 el = 0 outputfile = open("testPopenNonBlocking","wb") errorsfile = open("testPopenNonBlocking_err","wb") if channel: channel.setBlocking(False) while 1: if channel.eof(): print "EOF" break if not channel.poll(100,[SSH2.LIBSSH2_POLLFD_POLLIN,SSH2.LIBSSH2_POLLFD_POLLPRI]): print "no data" raise Exception('File incomplete') data = channel.read(BUFFER) # BUF represente la quantite maximum de donnees, mais on recuperer moins if data: sys.stdout.write(data) outputfile.write(data) l += len(data) errors = None if channel.poll(10,[SSH2.LIBSSH2_POLLFD_POLLEXT]): errors = channel.readstderr(BUFFER) print "\nerror\n" if errors is not None: sys.stderr.write("Error" + errors) el += len(errors) errorsfile.write(errors) ssh.close() print "data lenght: %s\nerror lenght: %s" %(l,el) time.sleep(2) >>I (half) solved the problem in non-blocking mode by polling for POLLERR (it >>seems to differs from the unix poll, as POLLERR is normally not significant >>in pollfd struct) "half", because since an error occurs, calling >>libssh2_poll on POLLERR success everytime. In that case, reading for stderr >>sipmly returns nothing (it doesn't block). > >Actually, I find very little use for libssh2_poll() at all... When is that >ever useful? Since connections etc already are done outside the library the >application already knows the sockets etc and could just as well just use >regular poll(). Or what am I missing? Maybe a I'm wrong on (libssh2_)poll use: I would to check if data is available before to try to read it, because in the case where is nothing to read, program waits infinitely for data (and as I said, channel EOF never matches in blocking mode after a channel_exec). I'm not experienced in network programming: basically, I just coded web php programs and a few libraries (as one php library which copes with IPP) -- Thomas Harding ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ libssh2-devel mailing list libssh2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libssh2-devel
