Intel XENIX 286 Programmers Guide (86) - Tenox.tc

csh: C Shell XENIX Programming
The notation
$#name
expands to the number of elements in the variable name. To illustrate, examine the
following terminal session (input is in boldface):
% set argv =(a b c)
1
% echo $#argv
3
% unset argv
% echo $?argv
0
% echo $argv
Undefi ned variable: argv.
%
You can also access the components of a variable that has several values. Thus
$argv[1]
gives the first component of argv or in the example above "a". Similarly
$argv[$#argv]
would give "c", and .
$argv[1-2]
would give "a b". Other notations useful in C shell scripts are
$n
where n is an integer. This is shorthand for
$argv[ n]
the nth parameter and
$*
which is a shorthand for
$argv
The form
$$
expands to the process number of the current C shell. Since this process number is
unique in the system, it is often used in the generation of unique temporary file names.
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