NSException When repeating NSTask - objective-c

Question

I have this code that is suppose to check certain settings and log the results. The first setting check works correctly but the next one fails. Here is the code block:
//init classes
CocoaLogging *logFile = [[CocoaLogging alloc]init];
NSString * result;
NSInteger * state;
NSPipe *pipe=[[NSPipe alloc] init];
NSFileHandle *handle;
NSString * cmd = [NSString stringWithFormat:#"%#", #"/usr/bin/defaults"];
//Start logging
NSString *logText;
NSString *logPath;
BOOL logSuccess;
NSLog(#"Start Settings Enforcer");
logPath = [NSString stringWithFormat:#"%#%#", NSHomeDirectory(), LOGFILE_PATH];
if (! [[NSFileManager defaultManager] fileExistsAtPath:logPath isDirectory:NO])
{
logSuccess = [logFile createLogFile:logPath];
if (logSuccess)
{
logText = [NSString stringWithFormat:#"%#", #"Start Settings Enforcer"];
[logFile makeLogEntry:logText to:logPath];
}
}
else
{
logPath = [NSString stringWithFormat:#"%#%#", NSHomeDirectory(), LOGFILE_PATH];
logText = [NSString stringWithFormat:#"%#", #"Start Settings Enforcer"];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
//check status of firewall
//defaults read "/Library/Preferences/com.apple.alf" globalstate
//array of commandline args
NSMutableArray *firewallArgs = [[NSMutableArray alloc]initWithObjects:#"-currentHost", #"read", #"/Library/Preferences/com.apple.alf", #"globalstate", nil];
//init the task
NSTask *firewall=[[NSTask alloc] init];
//define the command to run
[firewall setLaunchPath:cmd];
[firewall setArguments:firewallArgs];
[firewall setStandardOutput:pipe];
handle=[pipe fileHandleForReading];
//run the command
[firewall launch];
// convert NSData -> NSString
result = [[NSString alloc] initWithData:[handle readDataToEndOfFile]encoding:NSASCIIStringEncoding];
state = [result intValue];
NSLog(#"%#", result);
if (state == 1)
{
NSLog(#"firewall is on");
logText = [NSString stringWithFormat:#"%#", #"firewall is on"];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
else
{
NSLog(#"firewall is off");
logText = [NSString stringWithFormat:#"%#", #"firewall is off"];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
[firewallArgs removeAllObjects];
[handle closeFile];
[firewall terminate];
//check screensaver on
//defaults read ~/Library/Preferences/com.apple.screensaver askForPassword
NSString * plistPath = [NSString stringWithFormat:#"%#", #"~/Library/Preferences/com.apple.screensaver"];
plistPath = [plistPath stringByExpandingTildeInPath];
//array of commandline args
NSMutableArray *ssOnArgs = [[NSMutableArray alloc]initWithObjects:#"read", plistPath, #"askForPassword", nil];
//init the task
NSTask *ssOn=[[NSTask alloc] init];
//define the command to run
[ssOn setLaunchPath:cmd];
[ssOn setArguments:ssOnArgs];
[ssOn setStandardOutput:pipe];
handle=[pipe fileHandleForReading];
//run the command
[ssOn launch];
// convert NSData -> NSString
result = [[NSString alloc] initWithData:[handle readDataToEndOfFile]encoding:NSASCIIStringEncoding];
state = [result intValue];
if (state == 1)
{
NSLog(#"screensaver is on");
logText = [NSString stringWithFormat:#"%#", #"screensaver is on"];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
else
{
NSLog(#"screensaver is off");
logText = [NSString stringWithFormat:#"%#", #"screensaver is off"];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
NSLog(#"Check-in complete");
logText = [NSString stringWithFormat:#"%#", #"Check-in complete."];
logSuccess = [logFile makeLogEntry:logText to:logPath];
}
return 0;
}
Here is the error:
2014-03-31 12:58:11.630 SettingsEnforcer[5379:303] * Terminating app due to uncaught exception 'NSFileHandleOperationException', reason: ' -[NSConcreteFileHandle fileDescriptor]: No such process'
** First throw call stack:
(
0 CoreFoundation 0x00007fff8ce4825c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x00007fff8b075e75 objc_exception_throw + 43
2 CoreFoundation 0x00007fff8ce4810c +[NSException raise:format:] + 204
3 Foundation 0x00007fff8ba9a29d -[NSConcreteFileHandle fileDescriptor] + 30
4 Foundation 0x00007fff8bb2fb97 -[NSConcreteTask launchWithDictionary:] + 2114
5 SettingsEnforcer 0x0000000100001e1e main + 2126
6 libdyld.dylib 0x00007fff91e555fd start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
I hope someone smarter than I can spot the error.

Answer 1

You are recycling the NSPipe instance. Create a new pipe for the second task.