Get the Exit Status of a Remote SSH Command

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Demonstrates the Chilkat Ssh.GetChannelExitStatus method, which returns the remote process exit status for a channel. The only argument is the channel number. Call it only after ChannelReceivedExitStatus returns true.

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // Demonstrates the Ssh.GetChannelExitStatus method, which returns the remote process exit
    // status for a channel.  The only argument is the channel number.  Call it only after
    // ChannelReceivedExitStatus returns true.

    const ssh = try chilkat.Ssh.init();
    defer ssh.deinit();

    const ssh_port = 22;
    ssh.connect("ssh.example.com", ssh_port) catch {
        std.debug.print("{s}\n", .{try ssh.getLastErrorText(alloc)});
        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 password = "mySshPassword";

    ssh.authenticatePw("mySshLogin", password) catch {
        std.debug.print("{s}\n", .{try ssh.getLastErrorText(alloc)});
        return;
    };

    const channel_num = ssh.openSessionChannel();
    if (channel_num < 0) {
        std.debug.print("{s}\n", .{try ssh.getLastErrorText(alloc)});
        return;
    }

    ssh.sendReqExec(channel_num, "grep -q root /etc/passwd") catch {
        std.debug.print("{s}\n", .{try ssh.getLastErrorText(alloc)});
        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.setReadTimeoutMs(15000);

    ssh.channelReceiveToClose(channel_num) catch {
        std.debug.print("{s}\n", .{try ssh.getLastErrorText(alloc)});
        return;
    };

    // Retrieve the exit status immediately, before calling unrelated SSH methods or releasing the
    // channel, because the completed channel record can be discarded.
    if (ssh.channelReceivedExitStatus(channel_num)) {
        const exit_status = ssh.getChannelExitStatus(channel_num);
        std.debug.print("Exit status: {d}\n", .{exit_status});

        // By convention, 0 means the remote command succeeded.
        if (exit_status == 0) {
            std.debug.print("The remote command succeeded.\n", .{});
        } else {
            std.debug.print("The remote command reported a failure.\n", .{});
        }
    }

    ssh.disconnect();
}