macOS Shell Commands in Objective-C

[RevK]

Hello MacRumors;

I have been working on a few projects in Objective-C recently and have found it extremely difficult (if not impossible) to run a shell command/script from the code.

I have found this code for running a shell script from the resources folder:

NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/bin/sh"];
[task setArguments:[NSArray arrayWithObjects:[[NSBundle mainBundle] pathForResource:@"sscript" ofType:@"sh"], nil]];
[task launch];

The only thing is that I'd like to be able to use type the command right into the code; for example:

touch /Users/myusername/Desktop test.txt

Any help would be greatly appreciated, Thanks!

 

[Cromulent]

How about just using fork()?

 

[lee1210]

How about just using fork()?

or system()? (which forks, but does other things like invoking a shell to run your command, etc.)

 

[Cromulent]

or system()? (which forks, but does other things like invoking a shell to run your command, etc.)

Ah balls, I always get them mixed up. Yes system() would be a better function to use.

 

[Catfish_Man]

Hello MacRumors;

I have been working on a few projects in Objective-C recently and have found it extremely difficult (if not impossible) to run a shell command/script from the code.

I have found this code for running a shell script from the resources folder:

NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/bin/sh"];
[task setArguments:[NSArray arrayWithObjects:[[NSBundle mainBundle] pathForResource:@"sscript" ofType:@"sh"], nil]];
[task launch];

The only thing is that I'd like to be able to use type the command right into the code; for example:

touch /Users/myusername/Desktop test.txt

Any help would be greatly appreciated, Thanks!

Easy. Save the script to a temporary file and run that, or (I don't recall if sh/bash accepted input from stdin) pipe to stdin.

 

[RevK]

Would saving to a temporary file be as efficient as using system()?

I've heard bad things about using system().

Would way would be best for some simple commands?

 

[Cromulent]

I've heard bad things about using system().

What exactly?

 

[RevK]

What exactly?

From another forum post I found:


"You could use system() but it's use is proscribed.

NSTask would be the proper API supported method of doing it."

 

[lee1210]

From another forum post I found:


"You could use system() but it's use is proscribed.

NSTask would be the proper API supported method of doing it."

From the system() man page:

STANDARDS
     The system() function conforms to ISO/IEC 9899:1990 (``ISO C90'') and is
     expected to be IEEE Std 1003.2 (``POSIX.2'') compatible.

I'm more confident in that staying the same than NSTask.

-Lee

 

[RevK]

I tried using system() in a test project and it works great!

Thanks for showing me. You all are really awesome.