wakelock.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* This extremely simple program allows users/accounts to enable and disable wakelocks on Android based devices by to writing arbitray strings to /sys/power/wake_lock & /sys/power/wake_unlock. 

Use case:

On my device I am running a service inside of a chroot as a system account. Because said service runs under a restrictive account and not root it can not write to /sys/power/wake_* even when adding the sys account to the aid_wakelock Adroid group. Instead of stupidly allowing a system account to run commands as root using sudo or some other means that would almost certainly grant more capabilities than required I wrote this program.

*/

void help(void) {

//  printf("Wakelocker v1 by:\nGeofferey@github\n\n");
  printf("Useage ./wakelock [option] [string]:\n\n");

  printf("-l --lock      enable a wakelock\n");
  printf("-u --unlock    disable a wakelock\n\n");

  printf("e.g. # ./wakelock -u Android_wakelock\n");

}

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

  void lock(void) {

    FILE *lock_file = fopen("/sys/power/wake_lock", "a");

    if (lock_file == NULL) {

      printf("Could not open /sys/power/wake_lock\n");
      exit(0);

    }

    if (!(lock_file == NULL)) {

      fprintf(lock_file, "%s", argv[2]);
      fclose(lock_file);

      printf (argv[2]);
      printf (" wakelock enabled...\n");

    }

  }

  void unlock(void) {

    FILE *unlock_file = fopen("/sys/power/wake_unlock", "a");

    if (unlock_file == NULL) {

      printf("Could not open /sys/power/wake_unlock\n");
      exit(0);

    }

    if (!(unlock_file == NULL)) {

      fprintf(unlock_file, "%s", argv[2]);
      fclose(unlock_file);

      printf (argv[2]);
      printf(" wakelock disabled...\n");

    }

  }

  if (argc > 2) {

    if ((strcmp(argv[1], "--lock") == 0) || (strcmp(argv[1], "-l") == 0)) {

        lock();

    }

    else if ((strcmp(argv[1], "--unlock") == 0) || (strcmp(argv[1], "-u") == 0)) {

        unlock();

    }

    /*else if ((strcmp(argv[1], "--list") == 0) && (strcmp(argv[2], "--locks") == 0)) {

      list_locks();

    }*/

    else

        help();

  }

  else

    help();

  return 0;