C++
C++
Run a Command on an SSH Session Channel
See more SSH Examples
Demonstrates the Chilkat Ssh.SendReqExec method, which requests execution of a command on a session channel. The first argument is the channel number and the second is the command line. This example runs a command, reads the output until the channel closes, and prints it.
Background:
exec is the workhorse for automation: run one command, collect its output, and finish — no interactive shell needed. Note carefully that a true return means the request was accepted, not that the command succeeded. To learn the command's outcome, read its output and check the channel exit status.Chilkat C++ Downloads
#include <CkSsh.h>
void ChilkatSample(void)
{
bool success = false;
// Demonstrates the Ssh.SendReqExec method, which requests execution of a command on a session
// channel. The 1st argument is the channel number and the 2nd is the command line.
CkSsh ssh;
int sshPort = 22;
success = ssh.Connect("ssh.example.com",sshPort);
if (success == false) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
// Normally you would not hard-code the password in source. You should instead obtain it
// from an interactive prompt, environment variable, or a secrets vault.
const char *password = "mySshPassword";
success = ssh.AuthenticatePw("mySshLogin",password);
if (success == false) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
// Open a session channel. A negative return value indicates failure.
int channelNum = ssh.OpenSessionChannel();
if (channelNum < 0) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
// Request execution of a command. A true return means the server accepted the request; it
// does not mean the command itself succeeded.
success = ssh.SendReqExec(channelNum,"ls -l /tmp");
if (success == false) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
// IMPORTANT: Set a read timeout. ReadTimeoutMs defaults to 0, which means no limit -- without
// it, this call waits forever if the server never sends channel close.
ssh.put_ReadTimeoutMs(15000);
// Read the command output until the server closes the channel.
success = ssh.ChannelReceiveToClose(channelNum);
if (success == false) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
const char *output = ssh.getReceivedText(channelNum,"utf-8");
if (ssh.get_LastMethodSuccess() == false) {
std::cout << ssh.lastErrorText() << "\r\n";
return;
}
std::cout << output << "\r\n";
ssh.Disconnect();
}