usb-devs.c

/*

usbdevs - list mounted USB devices & their volume paths on Mac OS X

References:

- http://stackoverflow.com/questions/2459414/osx-how-to-get-a-volume-name-or-bsd-name-from-a-iousbdeviceinterface-or-locati
- http://superuser.com/questions/103755/whats-up-with-stat-on-mac-os-x-darwin-or-filesystems-without-names
- http://stackoverflow.com/questions/1698124/how-to-tell-if-a-given-path-is-mounted-removable-media-in-mac-os-x
- http://developer.apple.com/mac/library/samplecode/VolumeToBSDNode/Introduction/Intro.html

compile with:

gcc -Wall -O3 -x objective-c -fobjc-exceptions -framework Foundation -framework CoreFoundation      -framework IOKit -o usbdevs usbdevs.c

usage:

./usbdevs
./usbdevs -z | xargs -0 printf "%s\n"

*/

#import <stdio.h>
#import <stdlib.h>
#import <string.h>
#import <sys/param.h>
#import <sys/ucred.h>
#import <sys/mount.h>

#import <Foundation/Foundation.h>
#import <CoreFoundation/CoreFoundation.h>
#import <IOKit/IOKitLib.h>
#import <IOKit/IOMessage.h>
#import <IOKit/IOCFPlugIn.h>
#import <IOKit/usb/IOUSBLib.h>
#import <IOKit/IOBSD.h>



int main(int argc, char *argv[]) {

   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

   mach_port_t             master_port;
   kern_return_t           k_result = KERN_FAILURE;
   io_iterator_t           iterator = 0;
   io_service_t            usb_device_ref;
   CFMutableDictionaryRef  matching_dictionary = NULL; 

   char devicePath[MAXPATHLEN*2] = {0};

   int print0 = 0;
   size_t pathlen = 0;
   const char *deviceName = 0;
   CFStringRef bsdName = NULL;

   if (argc > 2) return 1;

   if (argc == 2)
   {
      if ( (strcmp(argv[1], "-z") == 0) )
      {
         print0 = 1;
      }
      else if ( (strcmp(argv[1], "-h") == 0) )
      {
         fprintf(stdout, "usage:  %s [-hz]\n\t-z: null-terminate output (ASCII nul character)\n", argv[0]); 
         return 0;
      }else{
         fprintf(stderr, "usage: %s [-hz]\n", argv[0]); 
         return 1;
      }
   }


   // man 2 getfsstat
   // getfsstat -- get list of all mounted file systems

   struct statfs *buf;
   int flags = MNT_NOWAIT, num_fs, num_stat, i;
   unsigned bufsz;

   num_fs = getfsstat(NULL, 0, flags);
   if (num_fs < 0) {
      perror("unable to count mounted filesystems: getfsstat");
      exit(1);
   }

   bufsz = sizeof(*buf) * num_fs;
   buf = malloc(bufsz);
   if (!buf) {
      perror("unable to allocate %u statfs structs");
      exit(1);
   }

   //fprintf(stderr, "p=%p\n", buf);

   num_stat = getfsstat(buf, bufsz, flags);
   if (num_stat < 0) {
       perror("unable to getfsstat");
       exit(1);
   }

   if (num_stat != num_fs) {
      fprintf(stderr, "Hmm, expected %u, got %d.\n", num_fs, num_stat);
   }


   // first create a master_port
   k_result = IOMasterPort(MACH_PORT_NULL, &master_port);
   if (KERN_SUCCESS != k_result) 
   {
      fprintf(stderr, "could not create master port, err = %d\n", k_result);
   }

   if ((matching_dictionary = IOServiceMatching(kIOUSBDeviceClassName)) == NULL)
   {
      fprintf(stderr, "could not create matching dictionary, err = %d\n", k_result);
   }

   k_result = IOServiceGetMatchingServices(master_port, matching_dictionary, &iterator);
   if (KERN_SUCCESS != k_result) 
   {
      fprintf(stderr, "could not find any matching services, err = %d\n", k_result);
   }

   while ((usb_device_ref = IOIteratorNext(iterator)))
   {
   
      bsdName = (CFStringRef) IORegistryEntrySearchCFProperty (usb_device_ref,
                                                               kIOServicePlane,
                                                               CFSTR ( kIOBSDNameKey ),
                                                               kCFAllocatorDefault,
                                                               kIORegistryIterateRecursively );
      if (!bsdName) continue;

      deviceName = [[NSString stringWithFormat: @"%@", bsdName] UTF8String];

      //printf("%s\n", deviceName);

      devicePath[0] = '\0';
      strcat(devicePath, "/dev/");
      strcat(devicePath, deviceName);

      pathlen = strlen(devicePath);

      //printf("pathlen: %zu\n", pathlen);
      //printf("devicePath: %s\n", devicePath);

      for (i = 0; i < num_stat; i++) {

         if (strncmp(buf[i].f_mntfromname, devicePath, pathlen) == 0)
         {
            if ( print0 == 0 )
               fprintf(stdout, "%s %s\n", buf[i].f_mntfromname, buf[i].f_mntonname);
            else
               fprintf(stdout, "%s %s%c", buf[i].f_mntfromname, buf[i].f_mntonname, 0);  
               // null-terminate output (ASCII nul character)
         }

      }

      CFRelease(bsdName);

      IOObjectRelease(usb_device_ref);            // no longer need this reference


   } // while


   [pool release];

   return 0;

}