Open System Services Porting Guide (G06.29+, H06.06+, J06.03+)

PSn Variable
The PSn variables determine the prompts used by the OSS shell. n is either 1 or 2, specifying the
primary or secondary prompt string. The default for PS1 is the dollar sign ($); the default for PS2
is the right angle bracket (>) followed by a blank space.
The following sample command sets the prompt to contain the user's name, the system name, the
current directory, and the current line number:
PS1=$LOGNAME@(uname -n):'$PWD'[\!]
If the user name is the super ID, the system name is OSS, and the current directory is /bin, the
prompt would look like the following:
SUPER.SUPER@OSS:/bin[21]
Aliases and Functions
Aliases allow the OSS shell to perform command-name or abbreviation substitutions. The value of
the current shell aliases can be printed using the alias command with no arguments.
Functions are similar to scripts, but without the overhead of searching the file system for the script
file. A function provides the ability to use the command-line parameters from its invocation and to
use any built-in or program. The currently defined functions can be listed using the typeset -f
command.
The following are examples of aliases and functions you can use in the OSS environment:
DescriptionAlias or Function
Establishes the h alias for the command history.alias h=history
Establishes an alias, specifying rename as a new name
for the mv command.
alias rename= ’mv’
Establishes the ll function, which produces a long listing
for the files specified in the command line.
function ll {ls -l $@ ;}
Establishes the lm function, which produces a long listing
for files specified in the command line and directs output
to the more command.
function lm {ls -l $@ | more ;}
stty Settings
The stty command allows you to specify terminal-control character values such as backspace,
linebreak, and End-of-File. The control character values can be printed using the stty -a command.
The following are sample stty commands:
stty eof ^D sets the End-of-File (EOF) control character to Ctrl-D.
stty erase ^H sets the erase character or backspace control character to Ctrl-H.
NOTE: The OSS shell has a default setting for the stty End-of-File (EOF) value of ^Y. On most
UNIX systems, the default value is ^D.
Line and History Editing
The OSS shell provides two command-line editing modes: escape activated and fc (FIX command)
activated. The following paragraphs describe editing command lines and history files. For a
tutorial-style discussion of editing command lines and history files, refer to the Open System Services
User’s Guide.
VISUAL or EDITOR Variables
When you press the Escape key, the built-in, shell command edit mode is activated. The editor
used is vi, emacs, or GNU emacs (gmacs). In this editing mode, either the current command or
a command from the history file can be edited and then executed. You can activate this facility
56 Interoperating Between User Environments