On Fri, 4 Sep 2009, Dmitry V. Krivenok wrote:
My program executes many remote commands like
ssh 192.168.70.205 cat /proc/meminfo | grep MemTotal | awk '{print $2}'
ssh 192.168.70.205 cat /proc/cpuinfo | grep processor | wc -l
ssh 192.168.70.205 uptime
ssh 192.168.70.205 "cat /proc/meminfo | grep MemTotal | awk '{print $2}'; cat
/proc/cpuinfo | grep processor | wc -l; uptime"
There. Three commands in one connection. No magic.
The question is can I use _current_ version of libssh2? Does it support: 1)
Creation of N "session" channels inside of SSH session and calling "exec" in
each channel? These channels should be active simultaneously, i.e. all
remote commands should run simultaneously.
Yes it does. Or at least should.
2) I consider every channel as a source of events ("new data available",
"command exited", "command was killed by signal", "error occurred"). I want
to implement event loop, so I need some kind of I/O multiplexing function,
which waits for requested events. To limit maximum execution time of remote
commands I should pass timeout to this function.
Is this a question?
libssh2 does not feature any fancy channel switch that can direct or map
actions on channels to specific events somehow. I bet that could be useful in
a scenario such as the one you describe.
3) If I found that remote command "hung", I should kill it via sending the
signal (SSH_MSG_CHANNEL_REQUEST with type "signal").
I don't think it supports that.
4) I need to read STDOUT/STDERR of remote command and get exit status.
I think you can get those.
I'm not sure that everything I need is already implemented in libssh2. If
not, is it possible to implement it using facilities provided by libssh2?
Everything within the SECSH protocol is possible to implement I'm sure.
--
/ daniel.haxx.se
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