Qshell is a command environment based on POSIX and X/Open standards.

It consists of the following two parts:

  • The shell interpreter (or qsh) is a program that reads commands from an input source, interprets each command, and then runs the command using the services of the operating system.
  • The utilities (or commands) are external programs that provide additional functions and can be quite simple or very complex.

Together, the shell interpreter and utilities provide a powerful, standards-based scripting environment. As you use the new programming models offered by i5/OS, Qshell provides an extensible command environment that allows you to do the followings tasks:

  • Manage files in any file system supported by the Integrated File System.
  • Run threaded programs that do thread-safe I/O to and from an interactive session.
  • Write shell scripts that can be run without modification on other systems using a cross-platform command language.
  • Write your own utilities to extend the functions provided by Qshell.

This topic provides both new and experienced users with the information needed to use Qshell commands and write Qshell scripts.

Note: In this information, the terms "job" and "process" are used interchangeably. The term "job" is from i5/OS and the term "process" is from POSIX.