Expressions, Comments, Syntax Tips
PCL Expressions
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Don’t break expressions in the middle of a keyword, constant, or identifier
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Multiple blanks are the same as a single blank space
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Lines beginning with “!” (bang operator) are echoed to the xterm (UNIX) or command window (NT), but are not executed
In MSC.Patran type: !`i` nodes created
In the xterm you see: %27 nodes created
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PCL expressions beginning with “>” are echoed to the session file
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P
CL expressions can be typed directly into MSC.Patran at the command line
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P
CL expressions may also be created with an editor in a text file and directed into MSC.Patran as a session file or by using the PCL directive !!INPUT
Identifiers Naming Conventions -
Function names and/or variable names are called identifiers
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Can be up to 32 characters long
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Must begin with a non-digit
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Case insensitive (as is all of PCL)
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Cannot be a reserved keyword, i.e., FOR, IF, etc.
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Valid identifiers
current_group
CurrentGroup
MyString
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Invalid identifiers
a_very_very_very_very_very_very_very_very_long_name
95abc
list
Identifiers
Variable / Function Scope -
Global variable names and functions share the same name space
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When two function names or two variable names conflict, the most recent addition supercedes the previous
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When function names and variable names conflict, the variable name takes precedence
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When compiling functions, PCL will indicate if a function name is superceded by writing “Cleared memory function” to the history window
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Hint: Use a unique prefix to keep function definitions separate, i.e au_do_this_and_that.pcl
Structure of a PCL Function Function Basics -
PCL functions begin with a FUNCTION statement and end with an END FUNCTION statement.
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The FUNCTION statement may contain an argument list to be passed in or out of the function.
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An optional RETURN statement can be used to return a calculated value from the function to the calling statement.
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Processing of the function terminates at either the END FUNCTION statement or a RETURN statement.
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There may be multiple RETURN statements within a single function.
Structure of a PCL Function
S
Function arguments (null)
FUNCTION a_very_simple_function()
/* This is a simple function that writes:
“$# My favorite number is 29”
in the MSC.Patran history window using 3 different
“write” or “print” statements.
*/
/* This is a comment. */
$ This is also a comment.
INTEGER MyFavoriteNumber
MyFavoriteNumber = 29
ui_writec(“My favorite number is %d \n”, MyFavoriteNumber)
ui_writef(“A21,1X,I3”, “My favorite number is”, MyFavoriteNumber)
ui_write(“My favorite number is “//STR_FROM_INTEGER(MyFavoriteNumber))
END FUNCTION /* a_very_simple_function */
Function declaration
Comments (Who we kidding? We all know that everyone loathes commenting their code!)
Variable declaration
Variable initialization
Statements or expressions
Function terminator
 
imple PCL function Example
S
tructure of a PCL Function
Sample output. The ui_write functions write text to the history window, the session file (patran.ses.##), and the journal file (model.db.jou)
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A
FUNCTION another_simple_function(MyFavoriteNumber)
INTEGER MyFavoriteNumber
INTEGER MyLeastFavoriteNumber
MyLeastFavoriteNumber = 13
ui_write(“My favorite number is “//str_from_integer(MyFavoriteNumber))
ui_write(“My least favorite number is “// @
str_from_integer(MyLeastFavoriteNumber))
END FUNCTION /* another_simple_function */
Function argument
Calling statement
nother simple PCL function
Note all variables must be declared, including function arguments
Calling statement
another_simple_function(29)
$
Sample output
 #My favorite number is 29
$#My least favorite number is 13
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