run /etc/rc.d

main.m

#import <Foundation/Foundation.h>
#import <Foundation/NSTask.h>

int main(){
    for (NSString *file in [[NSFileManager defaultManager] subpathsAtPath:@"/etc/rc.d"]) {
        NSString *path = [@"/etc/rc.d/" stringByAppendingString:file];
        if ([[NSFileManager defaultManager] isExecutableFileAtPath:path]) {
            [[NSTask launchedTaskWithLaunchPath:path arguments:@[]] waitUntilExit];
        }
    }
    return 0;
}