Appendix B. Reference Lists

Invocation Options

Here is a list of the options you can use when invoking the Korn shell. In addition to these, any set option can be used on the command line; see the table on options later in this appendix. Login shells are usually invoked with the options -i (interactive), -s (read from standard input), and -m -able job control).

OptionMeaning
-c string Execute string, then exit.
-s

Read commands from the standard input. If an argument is given, this flag takes precedence (i.e., the argument won’t be treated as a script name and standard input will be read).

-iInteractive shell. Ignore signals TERM, INTR, and QUIT.
-rRestricted shell. See Chapter 10.

Built-in Commands and Keywords

Here is a summary of all built-in commands and keywords.

CommandChapterSummary
: 7Do nothing (just do expansions of arguments).
. 4Read file and execute its contents in current shell.
alias 3Set up shorthand for command or command line.
bg 8Put job in background.
break 5

Exit from surrounding for, select, while, or until loop.

case 5Multi-way conditional construct.
cd 1Change working directory.
continue  

Skip to next iteration of for, select, while, or until loop.

echo 4Expand and print arguments (obsolete).
exec 9Replace shell with given program.
exit 5Exit from shell.
export 3Create environment variables.
eval 7Process arguments as a command line.
fc 2Fix command (edit history file).
fg 8Put background job in foreground.
for 5Looping construct.
function 4Define function. ...

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