SSH Reference Manual

For transferring files via SFTP rather than FTP, the application still uses the same APILIB, which is part of the HP
NonStop TCP/IP applications and utilities. However, APILIB is directed to start an SFTP rather than an FTP client. The
SFTP client will support the same inter-process communication messages like FTP, mapping the programmatic
commands it to the appropriate SFTP operations.
SSHAPI with SSHLIB
SSHLIB describes the external interface offered by the SSH application program interface (API). SSHLIB is used for
launching an SSH object and controlling it automatically by an application via the SSH API. SSHLIB can simplify the
task of controlling status or resources on a remote host. It is also helpful to automate setup scripts for duplicating
software package installations on different servers. There is no limitation for SSHLIB other than what the application
developer can imagine regarding remote control tasks executed via an SSH session.
In the figure above it is depicted how the application communicates with SSH using SSHLIB. When initiating an SSH
session via SSHLIB, the library will start an SSH process in SSH API server mode to handle the actual communication
for the application. SSHLIB will then communicate via inter-process messages (IPC) with the SSH process, mapping the
library calls to messages to be processed by SSH.
SSH will return required output and error information back to SSHLIB in the same fashion.
240 • Controlling SSH and SFTP Clients on NonStop via an API HP NonStop SSH Reference Manual