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

Question

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.

Answer 1

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];
}