Question

Im trying to list the details of specific processes using a UITableView. It displays perfectly when run on the Xcode simulator. However, it is malformed when deployed on the actual device. Perplexing thing is, when I perform the “ps aux” command on both the Mac and the iPhone, formatting of the outputs seem identical.

This is how it looks like in the simulator :

This is how it looks like on the real device :

Here is my code for the controller displaying these views :

viewDidLoad :

NSLog(@"myString is :%@", myString);
int processID = [myString intValue];

NSTask *task;
task = [[NSTask alloc] init];
[task setLaunchPath: @"/bin/ps"];

arguments = [NSArray arrayWithObjects: @"aux", [NSString stringWithFormat:@"%i", processID],nil];

[task setArguments: arguments];

NSPipe *pipe;
pipe = [NSPipe pipe];
//[task setStandardOutput: pipe];
[task setStandardOutput:pipe];

NSFileHandle *file;
file = [pipe fileHandleForReading];

[task launch];

NSData *data;
data = [file readDataToEndOfFile];

NSString *string;
string = [[NSString alloc] initWithData: data
                               encoding: NSUTF8StringEncoding];

//  NSLog(@"%@",string);


NSArray *lines= [string componentsSeparatedByString:@"\n"];

NSString *lastline = [lines objectAtIndex:[lines count]-2];
//  NSLog(@"%@",lastline);




lines2= [lastline componentsSeparatedByString:@" "];
NSLog(@"%@",lines2);
for (int i=0; i<[lines2 count]; i++) {

    if([[lines2 objectAtIndex:i] isEqualToString:@""]){
        [lines2 removeObjectAtIndex:i];
    }

}
for (int i=0; i<[lines2 count]; i++) {

    if([[lines2 objectAtIndex:i] isEqualToString:@""]){
        [lines2 removeObjectAtIndex:i];
    }

}


NSLog(@"Lines 2 is%@",lines2);
NSLog(@"Status is %@",[lines2 objectAtIndex:7]);


self.title = @"Process Info";

label = [[NSMutableArray alloc]init];

[label addObject:@"User:"];
[label addObject:@"Process ID:"];
[label addObject:@"CPU(%):"];
[label addObject:@"MEM(%):"];
[label addObject:@"VSZ:"];
[label addObject:@"RSS:"];
[label addObject:@"TT:"];
[label addObject:@"STAT:"];
[label addObject:@"Time Started:"];
[label addObject:@"Time Elapsed:"];
[label addObject:@"Launch Command:"];

[super viewDidLoad];

cellForRowAtIndexPath:

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

[cell setSelectionStyle:UITableViewCellSelectionStyleNone]; 
NSString *cellValue = [label objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;
cell.textColor = [UIColor colorWithRed:154.0/255.0 green:14.0/255.0 blue:2.0/255.0 alpha:1];
cell.font = [UIFont systemFontOfSize:16.0];


UILabel *label2 =  [[[UILabel alloc] initWithFrame:CGRectMake(120.0, 0, 240.0, 
                                                              tableView.rowHeight)] autorelease]; 


label2.font = [UIFont systemFontOfSize:16.0]; 
NSString *cellValue1 = [lines2 objectAtIndex:indexPath.row];
label2.text = cellValue1;
label2.textAlignment = UITextAlignmentLeft; 
label2.textColor = [UIColor blackColor]; 
label2.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | 
UIViewAutoresizingFlexibleHeight; 
[cell.contentView addSubview:label2]; 


return cell;

numberOfRowsInSection:

return [label count];

dealloc:

 [myString release];
[arguments release];
//[lines2 release];
[ResultStringID release];
[values release];
[label release];
[super dealloc];

The output of “ps aux” command on Mac :

The output of “ps aux” command on iPhone (Through an SSH shell) :

Answer 1

There’s no guarantee that ps on iOS does the same thing as on other platforms. There’s no UI that would allow a user to access the ps command on iOS devices, so you’re lucky that there’s a ps command at all. Try logging the output from the command to see what you’re getting, but don’t be surprised if there’s not much there.