HP-UX Reference (11i v3 07/02) - 1 User Commands A-M (vol 1)

k
ksh(1) ksh(1)
IFS Internal field separators, normally space, tab, and newline that are used to separate
command words resulting from command or parameter substitution, and for separat-
ing words with the special command
read. The first character of the
IFS parameter
is used to separate arguments for the
"$*"
substitution (see Quoting below).
HISTFILE If this parameter is set when the shell is invoked, its value is the path name of the file
that is used to store the command history. The default value is
$HOME/.sh_history
. If the user has appropriate privileges and no
HISTFILE is
given, then no history file is used (see Command Re-entry below).
HISTSIZE If this parameter is set when the shell is invoked, the number of previously entered
commands accessible to this shell will be greater than or equal to this number. The
default is 128.
HOME The default argument (home directory) for the
cd command.
MAIL If this parameter is set to the name of a mail file and the
MAILPATH parameter is
not set, the shell informs the user of arrival of mail in the specified file.
MAILCHECK This variable specifies how often (in seconds) the shell checks for changes in the
modification time of any of the files specified by the
MAILPATH or
MAIL parameters.
The default value is
600 seconds. When the time has elapsed the shell checks before
issuing the next prompt.
MAILPATH A list of file names separated by colons (:). If this parameter is set, the shell informs
the user of any modifications to the specified files that have occurred within the last
MAILCHECK seconds. Each file name can be followed by a ? and a message to be
printed, in which case the message undergoes parameter and command substitution
with the parameter $_ defined as the name of the changed file. The default message
is you have mail in $_.
PATH The search path for commands (see Execution below). The user cannot change PATH
if executing rksh (except in the .profile file).
PS1 The value of this parameter is expanded for parameter substitution, to define the pri-
mary prompt string which, by default, is $ followed by a space character. The char-
acter ! in the primary prompt string is replaced by the command number (see Com-
mand Re-entry below). To include a
! in the prompt, use !!.
PS2 Secondary prompt string, by default > followed by a space character.
PS3 Selection prompt string used within a select loop, by default #? followed by a
space character.
PS4 The value of this variable is expanded for parameter substitution and precedes each
line of an execution trace. If PS4 is unset, the execution trace prompt is + followed
by a space character.
SHELL The path name of the shell is kept in the environment. When invoked, the shell is
restricted if the value of this variable contains an
r in the basename.
TMOUT If set to a value greater than zero, the shell terminates if a command is not entered
within the prescribed number of seconds after issuing the
PS1 prompt.
VISUAL Invokes the corresponding option when the value of this variable ends in emacs,
gmacs,orvi (see set in Special Commands below).
The shell gives default values to PATH, PS1, PS2, MAILCHECK, TMOUT, and IFS. HOME, SHELL, ENV,
and MAIL are never set automatically by the shell (although HOME, SHELL, and MAIL are set by login(1)).
Blank Interpretation
After parameter and command substitution, the results of substitution are scanned for field separator char-
acters (found in
IFS), and split into distinct arguments where such characters are found. ksh retains
explicit null arguments ( or ’’) but removes implicit null arguments (those resulting from parameters that
have no values).
File Name Generation
Following substitution, each command word is processed as a pattern for file name expansion unless the
-f option has been set. The form of the patterns is the Pattern Matching Notation defined by regexp(5).
The word is replaced with sorted file names matching the pattern. If no file name is found that matches
494 Hewlett-Packard Company − 6 − HP-UX 11i Version 3: February 2007