Qshell Interpreter (qsh) - FTP Directory Listing - IBM

Parameters
Positional parameters
Special parameters
12 Qshell Interpreter (qsh)
A parameter is used to store data. You can access the value of a parameter by
preceding its name with a dollar sign ($) and surrounding the name with brackets ({
}). The brackets are optional when the name is a single digit, or a special
parameter, or the name is a single identifier. See “Parameter expansion” (page 16)
for more information on expanding the value of a parameter.
A positional parameter is a decimal number starting from one. Initially, qsh sets the
positional parameters to the command line arguments that follow the name of the
shell script. The positional parameters are temporarily replaced when a shell
function is called and can be reassigned using the set and shift utilities.
A special parameter is denoted by one of these special characters:
* (Positional parameters)
(Asterisk) Expands to the positional parameters, starting from one. When
the expansion occurs within a double-quoted string it expands to a single
field with the value of each parameter separated by the first character of the
IFS variable, or by a if IFS is unset.
@ (Positional parameters)
(Ampersand) Expands to the positional parameters, starting from one.
When the expansion occurs within double-quotes, each positional
parameter expands as a separate argument. If there are no positional
parameters, the expansion of @ generates zero arguments, even when @
is double-quoted.
# (Number of positional parameters)
(Number sign) Expands to the decimal number of positional parameters. It
is initially set to the number of arguments when qsh is invoked. It can be
changed by the set, shift, or dot utilities or by calling a function.
? (Exit status)
(Question mark) Expands to the decimal exit status of the most recent
command. A value of zero indicates successful completion. A non-zero
value indicates an error. A command ended by a signal has an exit status of
128 plus the signal number.
- (Option flags)
(Minus) Expands to the current option flags (the single-letter option names
concatenated into a string) as specified when qsh is invoked, by set, or
implicitly by qsh.
$ (Process ID of current shell)
(Dollar sign) Expands to the decimal process ID of the current shell. A
subshell retains the same value of $ as the current shell even if the
subshell is running in a different process.
! (Background process ID)
(Exclamation mark) Expands to the decimal process ID of the most recent
background command run from the current shell. For a pipeline, the
process ID is that of the last command in the pipeline.