Question

I don’t know why this method returns a blank string:

- (NSString *)installedGitLocation {     NSString *launchPath = @'/usr/bin/which';      // Set up the task     NSTask *task = [[NSTask alloc] init];     [task setLaunchPath:launchPath];     NSArray *args = [NSArray arrayWithObject:@'git'];     [task setArguments:args];      // Set the output pipe.     NSPipe *outPipe = [[NSPipe alloc] init];     [task setStandardOutput:outPipe];      [task launch];      NSData *data = [[outPipe fileHandleForReading] readDataToEndOfFile];     NSString *path = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];      return path; } 

If instead of passing @'git' as the argument, I pass @'which' I get /usr/bin/which returned as expected. So at least the principle works.

from the terminal

$ which which $ /usr/bin/which $ $ which git $ /usr/local/git/bin/git 

So it works there.

The only thing I can think of is that which isn’t searching through all the paths in my environment.

This is driving me crazy! Does anyone have any ideas?

EDIT: It looks like this is about setting up either NSTask or the user’s shell (e.g., ~/.bashrc) so that the correct environment ($PATH) is seen by NSTask.

Answer 1

Running a task via NSTask uses fork() and exec() to actually run the task. The user’s interactive shell isn’t involved at all. Since $PATH is (by and large) a shell concept, it doesn’t apply when you’re talking about running processes in some other fashion.