Executing sh file with sudo in OS X gives an error - objective-c

Question

I've developed an application where I need to run some script under root. Also sh script contains "sudo" commands. For running sh script under root I use STPrivilegedTask class from github:
https://github.com/sveinbjornt/STPrivilegedTask
Here how I run a script:
NSString *scriptPath = [[NSBundle mainBundle] pathForResource:#"my_script" ofType:#"sh"];
STPrivilegedTask *task = [[STPrivilegedTask alloc] initWithLaunchPath:scriptPath];
int result = [task launch]; // return error 60031 which means:
//errAuthorizationToolExecuteFailure = -60031, /* The specified program could not be executed. */
And here is a script I use:
#!/bin/bash
sudo mkdir -p /usr/local/myfolder
sudo su - root -c "launchctl load -F /System/Library/LaunchDaemons/com.mydaemon.daemon.plist"
I use OS X Mavericks 10.9.4
EDIT:
After I set "chmod +x my_script.sh" for script it runs script. But now I receive next errors in console:
sudo: no tty present and no askpass program specified
sudo: no tty present and no askpass program specified
Seems that my admin credentials I put didn't applied with script I run. Any ideas how to fix that?

Answer 1

Here are two solutions taken in part from this stackexchange thread, which I can't test because I do not currently own a mac.
Solution 1: Use OSAScript to run the command in the first place
#!/bin/bash
sudo mkdir -p /usr/local/myfolder
osascript -e "do shell script \"mkdir -p /usr/local/myfolder\" with administrator privileges"
osascript -e "do shell script \"launchctl load -F /System/Library/LaunchDaemons/com.mydaemon.daemon.plist\" with administrator privileges"
Solution 2: Use OSAScript to prompt for a password and use that with sudo
#!/bin/bash
pw = "$(osascript -e 'Tell application "System Events" to display dialog "Password:" default answer "" with hidden answer' -e 'text returned of result' 2>/dev/null)"
echo $pw | sudo -S mkdir -p /usr/local/myfolder
echo $pw | sudo -S su - root -c "launchctl load -F /System/Library/LaunchDaemons/com.mydaemon.daemon.plist"

Answer 2

If you're using STPrivilegedTask properly, then the script should already be running with root privileges so the sudo commands are actually not needed in that case.
You should use something akin to:
sudo=
[[ $(id -u) != 0 ]] && sudo=sudo
$sudo <command that would need sudo>
which should prevent the errors about not having a tty, which are related to invoking the sudo command in a GUI application.