compile ok. function partially ok.

TESTING:
m@debian:/home/softz/zbaidu_pssh$ curl -d '[{"hostname":"127.0.0.1","username":"de","password":"sdf","command":"ps"},{"hostname":"baibaibai","username":"root","password":"123","command":"ls"}]' 127.0.0.1:9999
  PID TTY          TIME CMD
 2335 ?        00:42:32 amuled
 2430 ?        00:50:47 transmission-da
 7339 ?        00:00:00 dbus-daemon
 7341 ?        00:00:00 gvfsd
 7347 ?        00:00:01 gvfs-gdu-volume
 7349 ?        00:00:06 gvfs-afc-volume
 7352 ?        00:00:00 gvfs-gphoto2-vo
 7354 ?        00:00:00 gvfsd-trash
 7356 ?        00:00:00 gvfsd-network
 7360 ?        00:00:00 gvfsd-smb-brows
 7366 ?        00:00:00 gnome-keyring-d
 7372 ?        00:00:00 gvfsd-dnssd
 9240 ?        00:00:00 dbus-daemon
 9242 ?        00:00:00 gvfsd
 9248 ?        00:00:01 gvfs-gdu-volume
 9253 ?        00:00:06 gvfs-afc-volume
 9257 ?        00:00:00 gvfs-gphoto2-vo
 9259 ?        00:00:00 gvfsd-trash
 9261 ?        00:00:00 gvfsd-network
 9265 ?        00:00:00 gvfsd-smb-brows
 9271 ?        00:00:00 gnome-keyring-d
 9284 ?        00:00:00 gvfsd-dnssd
11128 ?        00:00:00 dbus-daemon
11130 ?        00:00:00 gvfsd
11136 ?        00:00:01 gvfs-gdu-volume
11141 ?        00:00:06 gvfs-afc-volume
11144 ?        00:00:00 gvfs-gphoto2-vo
11146 ?        00:00:00 gvfsd-trash
11148 ?        00:00:00 gvfsd-network
11151 ?        00:00:00 gvfsd-smb-brows
11158 ?        00:00:00 gnome-keyring-d
11164 ?        00:00:00 gvfsd-dnssd
11175 ?        00:00:00 gvfsd-metadata
11786 ?        00:00:00 sshd
11787 ?        00:00:00 ps
21693 ?        00:00:00 dbus-daemon
21695 ?        00:00:00 gvfsd
21701 ?        00:00:01 gvfs-gdu-volume
21703 ?        00:00:07 gvfs-afc-volume
21706 ?        00:00:00 gvfs-gphoto2-vo
21708 ?        00:00:00 gvfsd-trash
21710 ?        00:00:00 gvfsd-network
21714 ?        00:00:00 gvfsd-smb-brows
21720 ?        00:00:00 gnome-keyring-d
21726 ?        00:00:00 gvfsd-dnssd
21735 ?        00:00:00 dbus-daemon
21737 ?        00:00:00 gvfsd
21743 ?        00:00:01 gvfs-gdu-volume
21745 ?        00:00:07 gvfs-afc-volume
21748 ?        00:00:00 gvfs-gphoto2-vo
21750 ?        00:00:00 gvfsd-trash
21752 ?        00:00:00 gvfsd-network
21755 ?        00:00:00 gvfsd-smb-brows
21762 ?        00:00:00 gnome-keyring-d
21768 ?        00:00:00 gvfsd-dnssd
22156 ?        00:00:00 dbus-daemon
22158 ?        00:00:00 gvfsd
22164 ?        00:00:01 gvfs-gdu-volume
22166 ?        00:00:07 gvfs-afc-volume
22169 ?        00:00:00 gvfs-gphoto2-vo
22171 ?        00:00:00 gvfsd-trash
22173 ?        00:00:00 gvfsd-network
22176 ?        00:00:00 gvfsd-smb-brows
22183 ?        00:00:00 gnome-keyring-d
22189 ?        00:00:00 gvfsd-dnssd
22208 ?        00:00:00 gvfsd-metadata
HTTP/1.1 500 Internal Server Error
m@debian:/home/softz/zbaidu_pssh$