Korn shell
The Korn shell (ksh command) is backwardly compatible with the
Bourne shell (bsh command) and contains most of the Bourne shell features
as well as several of the best features of the C shell.
Variables set by the Korn shell or POSIX shell
The following are variables that are set by the shell.
Variables used by the Korn shell or POSIX shell
The following are variables that are used by the shell.
Command substitution in the Korn shell or POSIX shell
The Korn Shell, or POSIX Shell, lets you perform command substitution. In command substitution, the shell executes a specified command in a subshell environment and replaces that command with its output.
Arithmetic evaluation in the Korn shell or POSIX shell
The Korn shell or POSIX shell regular built-in let command enables you to perform integer arithmetic.
Field splitting in the Korn shell or POSIX shell
After performing command substitution, the Korn shell scans the results of substitutions for those field separator characters found in the IFS (Internal Field Separator) variable. Where such characters are found, the shell splits the substitutions into distinct arguments.
List of Korn shell or POSIX shell special built-in commands
Special commands are built into the Korn shell and POSIX shell and executed in the shell process.
Korn shell or POSIX shell regular built-in commands
The following is a list of the Korn shell or POSIX shell regular built-in commands.
Conditional expressions for the Korn shell or POSIX shell
A conditional expression is used with the [[
compound command to test attributes of files and to compare strings.
Quotation of characters in the Korn shell or POSIX shell
When you want the Korn shell or POSIX shell to read a character as a regular character, rather than with any normally associated meaning, you must quote it.
Restricted Korn shell
The Restricted Korn Shell is used to set up login names and execution environments whose capabilities are more controlled than those of the regular Korn shell.
Reserved words in the Korn shell or POSIX shell
The following reserved words have special meaning to the Korn shell or POSIX shell.
Enhanced Korn shell (ksh93)
In addition to the default system Korn shell (/usr/bin/ksh ), AIX® provides an enhanced version available as Korn shell /usr/bin/ksh93 . This enhanced version is mostly upwardly compatible with the current default version, and includes a few additional features that are not available in Korn shell /usr/bin/ksh .
Exit status in the Korn shell or POSIX shell
Errors detected by the shell, such as syntax errors, cause the shell to return a nonzero exit status. Otherwise, the shell returns the exit status of the last command carried out.
Parameters in the Korn shell
Korn shell parameters are discussed below.
File name substitution in the Korn shell or POSIX shell
The Korn shell, or POSIX shell, performs file name substitution by scanning each command word specified by the Word variable for certain characters.
Input and output redirection in the Korn shell or POSIX shell
Before the Korn shell executes a command, it scans the command line for redirection characters. These special notations direct the shell to redirect input and output.
Korn shell or POSIX shell built-in commands
Special commands are built in to the Korn shell and POSIX shell and executed in the shell process.
Job control in the Korn shell or POSIX shell
The Korn shell, or POSIX shell, provides a facility to control command sequences, or jobs .
Inline editing in the Korn shell or POSIX shell
Normally, you type each command line from a terminal device and follow it by a newline character (RETURN or LINE FEED ). When you activate the emacs, gmacs, or vi inline editing option, you can edit the command line.
Korn shell or POSIX shell commands
The Korn shell is an interactive command interpreter and command programming language. It conforms to the Portable Operating System Interface for Computer Environments (POSIX), an international standard for operating systems.
Command aliasing in the Korn shell or POSIX shell
The Korn shell, or POSIX shell, allows you to create aliases to customize commands.