ACL is Arbortext’s Command Language. It is similar to Perl, which I really like. See Part 1 and Part 2.
Variables
A variable is a keyword or phrase that is linked to a “value” stored in memory or an expression that can be evaluated. For instance, a variable might be called “total_count” and contains a number. Variables are usually defined in ACL beginning with a dollar sign ($), they do not have to, but it is very good practice. The variable is on the left side and the value is on the right of the assignment operator (=). When assigning variables, it best to read right to left. For example, assigning the string or text, “red” with the equal sign (=), to a variable “color”. It is a good practice to end your assignments with a semi-colon (;).
$color = red;
Some common variable assignments using expressions.
#— Machine Name
$machine =
$main::
ENV[‘COMPUTERNAME’];
#— User’s Name
$user = username();
Variable Scope
Variables exist in two locations or scopes, Global and Local.
The default is Local. It is a good practice to define the minimum amount of scope needed or limiting your variables. This is helpful in maintaining the code and debugging it. For example, it may be confusing if a variable is a Global $A and a Local variable called $A are both being used in a For-Each loop.
Global variables are accessible anywhere in the ACL code.
Tip: If defining a Global Variable, pick a naming convention such as all caps. This will be helpful when mixing Local and Global variables in code. For Local variables, choose, for example, Camel Case.
global $DEBUG = 1;
local $UserName =
"Tester";
Local variables can be limited by a block of code (code inside the { }). When variables are assigned, inside blocks are local or limited just to that block. Blocks can be found in functions and items inside conditionals, such as an if statement.
function findTMnumberName
() {
mark -
select end
$tmname =
$selection #local variable
gsub
(‘^P’,
”,
$tmname);
gsub
(‘^V’,
”,
$tmname);
$TMnumber =
$TM_NAME[$tmname];
#local variables, global $TM_NAME
response
($TMnumber);
caret
0,
"<title>" -t
is -pd
"$TMnumber";
}Shortcut Assignments
If using a number variable as a counter, and the counter needs to increment by one, you could do:
$lineNumber = $lineNumer +1;
A shortcut using the (+=) means increment and assign the value to itself.
$lineNumber += 1;
If using a string variable using the dot operator (.) to concatenate or stitch together strings.
$message = "File " . doc_name() . " sent to be published!";
The variable $message resolves as “File Chapter 2 sent to be published!” if doc_name() was equivalent to “Chapter 2″.
Variable Evaluation
Variables inside double quotes will be evaluated, and variables inside single quotes are not evaluated.
$username = "Tester";
$message = "Hello $username!";
Returns “Hello Tester!”
$username = "Tester";
$message = ‘Hello $username!’;
Returns “Hello $username!”
Comparative
Using variables for comparison. In a “if” statement, you may want the variable, if true, then do something with it. Comparisons can be strings equaling or not equaling other strings. As well as, numbers equaling (==), not equaling (!=), greater (>), lesser (<), greater or equal (>=) or less than or equal (<=) to other numbers.
String comparisons (==):
if ($machine == "Dell") {
response("machine is a Dell");
} else if (match($machine ,"HP*" ) {
response("machine is not a Dell, but some HP Model");
}
Number comparison (==, >, <, !=, <=, >=)
if ($status !=0) {
message "You must select something first”; #Not equal to zero
}
