unable to detect application running with another user (via switch user)

Use case: I login as "user1" and launch Safari, then I click "user1" on top-right corner and switch user to "user2". Now, I am trying to detect whether Safari is running for "user1" but I am unable to do so with standard calls. I am using OS X 10.8 Mountain Lion for both development and running my code.

I have used the following but in vain:

[[NSWorkspace sharedWorkspace] runningApplications] - Safari not there in the list
GetNextProcess() - Safari does not come up
GetProcessForPID() - I get an error "no such process"

But when I do a ps -aef | grep Safari from the terminal, I can see Safari. (This is not only the case with Safari but other applications as well.)

Can someone please help. Thank you very much.

You can use sysctl or ps command to get a list of all BSD processes.Have a look at Technical Q&A QA1123

#include <sys/sysctl.h>
#include <pwd.h>
typedef struct kinfo_proc kinfo_proc;

static int GetBSDProcessList(kinfo_proc **procList, size_t *procCount)
// Returns a list of all BSD processes on the system.  This routine
// allocates the list and puts it in *procList and a count of the
// number of entries in *procCount.  You are responsible for freeing
// this list (use "free" from System framework).
// On success, the function returns 0.
// On error, the function returns a BSD errno value.
{
    int                 err;
    kinfo_proc *        result;
    bool                done;
    static const int    name[] = { CTL_KERN, KERN_PROC, KERN_PROC_ALL, 0 };
    // Declaring name as const requires us to cast it when passing it to
    // sysctl because the prototype doesn't include the const modifier.
    size_t              length;

    //    assert( procList != NULL);
    //    assert(*procList == NULL);
    //    assert(procCount != NULL);

    *procCount = 0;

    // We start by calling sysctl with result == NULL and length == 0.
    // That will succeed, and set length to the appropriate length.
    // We then allocate a buffer of that size and call sysctl again
    // with that buffer.  If that succeeds, we're done.  If that fails
    // with ENOMEM, we have to throw away our buffer and loop.  Note
    // that the loop causes use to call sysctl with NULL again; this
    // is necessary because the ENOMEM failure case sets length to
    // the amount of data returned, not the amount of data that
    // could have been returned.

    result = NULL;
    done = false;
    do {
        assert(result == NULL);

        // Call sysctl with a NULL buffer.

        length = 0;
        err = sysctl( (int *) name, (sizeof(name) / sizeof(*name)) - 1,
                     NULL, &length,
                     NULL, 0);
        if (err == -1) {
            err = errno;
        }

        // Allocate an appropriately sized buffer based on the results
        // from the previous call.

        if (err == 0) {
            result = malloc(length);
            if (result == NULL) {
                err = ENOMEM;
            }
        }

        // Call sysctl again with the new buffer.  If we get an ENOMEM
        // error, toss away our buffer and start again.

        if (err == 0) {
            err = sysctl( (int *) name, (sizeof(name) / sizeof(*name)) - 1,
                         result, &length,
                         NULL, 0);
            if (err == -1) {
                err = errno;
            }
            if (err == 0) {
                done = true;
            } else if (err == ENOMEM) {
                assert(result != NULL);
                free(result);
                result = NULL;
                err = 0;
            }
        }
    } while (err == 0 && ! done);

    // Clean up and establish post conditions.

    if (err != 0 && result != NULL) {
        free(result);
        result = NULL;
    }
    *procList = result;
    if (err == 0) {
        *procCount = length / sizeof(kinfo_proc);
    }

    assert( (err == 0) == (*procList != NULL) );

    return err;
}

+ (NSArray*)getBSDProcessList
{
    kinfo_proc *mylist =NULL;
    size_t mycount = 0;
    GetBSDProcessList(&mylist, &mycount);

    NSMutableArray *processes = [NSMutableArray arrayWithCapacity:(int)mycount];

    for (int i = 0; i < mycount; i++) {
        struct kinfo_proc *currentProcess = &mylist[i];
        struct passwd *user = getpwuid(currentProcess->kp_eproc.e_ucred.cr_uid);
        NSMutableDictionary *entry = [NSMutableDictionary dictionaryWithCapacity:4];

        NSNumber *processID = [NSNumber numberWithInt:currentProcess->kp_proc.p_pid];
        NSString *processName = [NSString stringWithFormat: @"%s",currentProcess->kp_proc.p_comm];
        if (processID)[entry setObject:processID forKey:@"processID"];
        if (processName)[entry setObject:processName forKey:@"processName"];

        if (user){
            NSNumber *userID = [NSNumber numberWithUnsignedInt:currentProcess->kp_eproc.e_ucred.cr_uid];
            NSString *userName = [NSString stringWithFormat: @"%s",user->pw_name];

            if (userID)[entry setObject:userID forKey:@"userID"];
            if (userName)[entry setObject:userName forKey:@"userName"];
        }

        [processes addObject:[NSDictionary dictionaryWithDictionary:entry]];
    }
    free(mylist);

    return [NSArray arrayWithArray:processes];
}

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