All DatabasesInside Mac - Basic Toolbox
Using the Process Manager
Using the Process Manager Information for scheduling all processes
The Process Manager assigns a process serial number to each open
application (or desk accessory, if it is not opened in the context of an
application). The process serial number is unique to each process on the local
machine and is valid for a single boot of the machine. You can use the process
serial number to specify a particular process for most of the
Process Manager routines. You can use the process serial number returned
from the GetCurrentProcess , GetNextProcess , GetFrontProcess ,
and LaunchApplication functions in other Process Manager routines.
Opening or Printing Files Based on Finder Information
When a user opens or prints a file from the Finder, the Finder uses the
Process Manager to launch the application that created the file. The Finder
sets up the information your application can use to determine which files to
open or print. The Finder information includes a list of files to open or print.
In version 7.0, applications that support high-level events (that is, that have
the isHighLevelEventAware flag set in the 'SIZE' resource) receive the Finder
information through Apple events. The Apple Event Manager describes how
your application processes Apple events to open or print files.
Applications that do not support high-level events can use the
CountAppFiles , GetAppFiles , and ClrAppFiles routines or the
GetAppParms routine to get the Finder information. See the section called,
Segment Loader for information on these routines.
Getting Information About Other Processes
You can use the GetNextProcess , GetFrontProcess , or
GetCurrentProcess functions to get the process serial number of a
process. The GetCurrentProcess function returns the process serial
number of the process that is currently executing. The current process is the
process whose A5 world is currently valid; this process can be in the
background or foreground. The GetFrontProcess function returns the
process serial number of the foreground process. For example, if your process
is running in the background, you can use GetFrontProcess to determine
which process is in the foreground.
The Process Manager maintains a list of all open processes. You can specify
the process serial number of a process currently in the list and use
GetNextProcess to get the process serial number of the next process in the
list. The interpretation of the value of a process serial number and the order
of the list of processes is internal to the Process Manager.
When specifying a particular process, use only a process serial number
returned by a high-level event, Process Manager routine, or constants
defined by the Process Manager. You can use these constants to specify
special processes.
kNoProcess //process does not exist
kSystemProcess //process belongs to OS
kCurrentProcess //the current process
In all Process Manager routines, the constant kNoProcess refers to a
process that does not exist, the constant kSystemProcess refers to a process
belonging to the Operating System, and the constant kCurrentProcess refers to
the current process.
To begin enumerating a list of processes, use the GetNextProcess function
and specify the constant kNoProcess as the parameter to return the process
serial number of the first process in the list. You can use the returned process
serial number to get the process serial number of the next process in the list.
The GetNextProcess function returns the constant kNoProcess and the result
code procNotFound at the end of the list.
You can also use a process serial number to specify a target application when
your application sends a high-level event. See the Event Manager for
information on how to use a process serial number when your application
sends a high-level event.
You can use the GetProcessInformation function to obtain information
about any process, including your own. For example, for a specified process,
you can find the application's name as it appears in the Application menu, the
type and signature of the application, the number of bytes in the application
partition, the number of free bytes in the application heap, the application that
launched the application, and other information.
The GetProcessInformation function returns information about the
requested process in a process information record. The process information
record is defined by the ProcessInfoRec data type.
// Searching for a specific process
// Assuming inclusion of
#include <Processes.h>
Boolean FindAProcess (OSType signature, ProcessSerialNumber
* process,ProcessInfoRec *infoRec,
FSSpecPtr aFSSpecPtr);
Boolean FindAProcess (OSType signature, ProcessSerialNumber * process,
ProcessInfoRec *infoRec, FSSpecPtr
aFSSpecPtr)
{
process->highLongOfPSN = 0;
process->lowLongOfPSN = kNoProcess; // start from the beginning
infoRec-> processInfoLength = sizeof(ProcessInfoRec);
infoRec-> processName = (StringPtr) NewPtr(32);
infoRec-> processAppSpec = aFSSpecPtr;
while (!GetNextProcess( process)) {
if ( GetProcessInformation( process, infoRec) ) {
if ( (infoRec-> processType == (long) 'APPL') &&
(infoRec-> processSignature == signature) )
return TRUE; [TOKEN:12079] found the process
}
} // while
return FALSE;
}
The code example shows how you can use the GetNextProcess function with
the GetProcessInformation function to search the process list for a
specific process.
The code searches the process list for the application with the specified
signature. For example, you might want to find a specific process in order to
send a high-level event to it.
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