#DependsOn

This command can be used to indicate a dependancy that is not obvious to PPWIZARD. All input and output files seen by PPWIZARD are automatically taken care of but there may be instances where you might need to indicate other files.

As an example of an INPUT dependancy, you might have a macro which reads parts of CONFIG.SYS (only you know why!) using the rexx linein() function, because your generated output is dependant on the contents of CONFIG.SYS you will wish to rebuild if the file changes.

As an example of an OUTPUT dependancy, you might not wish to use the #output command and therefore directly write to files using a rexx "lineout()" function.

A file input dependancy should be defined before the file is used as this ensures that ppwizard can detect changes to the input file even while it is executing. It does not matter when an output dependancy is defined as the timestamp is only read at completion.

If /DependsOn was not specified then the command is ignored.

Syntax

[WhiteSpace]#DependsOn  ["]DepType["]  ["]StampWhat1["]  ...

The "DepType" parameter indicates should be one of:

• INPUT
  The following information is an input dependancy. Note that PPWIZARD can look at other things and not just input files (as explained below). The rexx AddInputFileToDependancyList() routine can also be used.

• OUTPUT
  The following file(s) are output (target) file dependancies. The rexx AddOutputFileToDependancyList() routine can also be used.

• TEMP
  The following file(s) are temporary files and should be ignored. This can be used before or after a file is marked as an input or output dependancy. The filename should be specified as it appears in the generated dependancy file (same relative or absolute filename). The rexx AddTempFileToDependancyList() routine can also be used.

A rebuild of your target files is required if there are any input files which have a later date/time than any of your output files (ppwizard actually only cares if file timestamps have changes, it does not matter whether a file becomes newer or older). A rebuild is also forced if an input or output file can't be located.

It is not an error (just time consuming) to specify the same item more than once.

The "StampWhat" parameter(s) are usually the names of individual files (not file masks) however for "INPUT" dependancies if an item starts with a "*" then it should be one of the following codes:

• *CmdLine
  Use this to indicate that you wish ppwizard to examine the command line switches (masks ignored). If different switches were used then a remake is required. This dependancy is on by default (see the /DependsOnComplete switch).

• *Exec=CommandLine
  This allows a you to process any command that can be typed at a command line. Its redirected output, stripped of carriage return, Line Feed and End Of File characters is used as the "stamp".

• *Expires=When
  This indicates that at some time in the future you wish to force a rebuild. The "When" parameter has the same syntax as the offset passed to the TimeStamp() routine except that you can use "NOW" to represent 0 (always rebuild). Also see the "*Today" type.

• *Today
  Use this to indicate that you do not need a rebuild today but you would tomorrow. Note that you could use "*Expires" with a period of "1d" (one day) but that is 24 hours elapsed and "*today" simply looks at the date and completely ignores the time.

  One example of why you might want to do this is my DLCNTR ppwizard add-on where it marks "new" downloads if they are recent, I need to check if recent every day.

• *Files=[+]FileMask
  This allows a list of files matching a mask to be stamped in one hit. Unlike simple stamping of individual files this uses the mask to determine differences so it will detect file additions and not just deletions and modifications to already known files. For example "*Files=+E:\DB\URLS\*.*" will stamp all files in the directory, and since "+" was used will also process those in its subdirectories.

• *PpwPgm
  Use this to indicate that you wish ppwizard to rebuild if the version of ppwizard changes in any way. This dependancy is on by default (see the /DependsOnComplete switch).

• *Rexx=Expression(s)
  This allows a you to process some rexx and return a value. The value to be used should be returned in the rexx variable DepValue, if your rexx code does not include "DepValue" (any case) then it is assumed to be a single rexx expression which can safely be assigned to that variable.

  One good example of how to use this is where your build depends on the value of an environment variable (although in this case a "*Exec" of the "set" command would also work in most operating systems).

If you wish to specify a whole group of individual files matching a mask then I would suggest the use of "*files", however this only works for "input" dependencies, have a look at the "Adding Dependencies via a File Mask" section for an example of how to do this for other types.

Example 1 - Assorted TIME related Commands

The following could be used to force a compile at or after a particular date (this would be handy if your page includes information that is obsolete after a specific date):

#DependsOn INPUT ^*Rexx=date('Standard') >= '20030114'^

The following could be used to force a compile at the start of each new year so that your pages can update any copyright messages etc:

#DependsOn INPUT ^*Rexx=left( date('Standard'), 4)^

The following uses "Expires" to ensure that a build occurs at least once per day:

#DependsOn INPUT ^*Expires=1d^

Other "tests":

#DependsOn INPUT '*TODAY'        ;;Rebuild tomorrow
#DependsOn INPUT '*EXPIRES=1w'   ;;Rebuild in another week
#DependsOn INPUT '*EXPIRES=3H'   ;;rebuild in 3 hours
#DependsOn INPUT '*EXPIRES=NOW'  ;;Must always rebuild

Of course as well as using the standard rexx date() and time() built in functions you could use BaseDate(), TimeStamp() or any routine built by anyone (rexx, therefore PPWIZARD can execute external functions).

Example 2 - Assorted Commands

#DependsOn INPUT "*CMDLINE"      ;;If command line switches change
#DependsOn INPUT "*PpWPGM"       ;;If ppwizard program changes in any way
#DependsOn INPUT ^*Rexx=getenv('ppwizard_include')^ ;;If the environment variable changes

Example 3 - Two files specified

#DependsOn  INPUT   "C:\CONFIG.SYS"   "C:\STARTUP.CMD"

Example 4 - Real life macro

   ;--- Outputs the size of a file (takes parameter "File") --------------------
   #( ''
       #define SizeOfFile
       #evaluate+  LocalFileName    ^ReplaceString("../{$File}", "/", "\")^
       #DependsOn  INPUT            "<$LocalFileName>"
       #evaluate+  TmpFileSize      ^FileQuerySize("<$LocalFileName>")^
       #if "<$TmpFileSize>" = ""
           #error $Failed getting size of "<$LocalFileName>"$
       #endif
       <$TmpFileSize $$AddComma>
   #)
   #define SizeOfFileInSmallFont   <FONT SIZE=-1>{$Before=""}<$SizeOfFile File=*{$File}*> bytes{$After=""}</FONT>
   #define (SizeOfFileInSmallFont) <$SizeOfFileInSmallFont File=*{$File}* Before='(' After=')'>

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PPWIZARD Manual

Saturday May 28 2022 at 2:55pm