text: /*
   * Copyright (C) 2008 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/wait.h>
  #include <unistd.h>
  
  #include <logwrap/logwrap.h>
  #include <cutils/klog.h>
  
  #include "cutils/log.h"
  
  void fatal(const char *msg) {
      fprintf(stderr, "%s", msg);
      ALOG(LOG_ERROR, "logwrapper", "%s", msg);
      exit(-1);
  }
  
  void usage() {
      fatal(
          "Usage: logwrapper [-a] [-d] [-k] BINARY [ARGS ...]\n"
          "\n"
          "Forks and executes BINARY ARGS, redirecting stdout and stderr to\n"
          "the Android logging system. Tag is set to BINARY, priority is\n"
          "always LOG_INFO.\n"
          "\n"
          "-a: Causes logwrapper to do abbreviated logging.\n"
          "    This logs up to the first 4K and last 4K of the command\n"
          "    being run, and logs the output when the command exits\n"
          "-d: Causes logwrapper to SIGSEGV when BINARY terminates\n"
          "    fault address is set to the status of wait()\n"
          "-k: Causes logwrapper to log to the kernel log instead of\n"
          "    the Android system log\n");
  }
  
  int main(int argc, char* argv[]) {
      int seg_fault_on_exit = 0;
      int log_target = LOG_ALOG;
      bool abbreviated = false;
      int ch;
      int status = 0xAAAA;
      int rc;
  
      while ((ch = getopt(argc, argv, "adk")) != -1) {
          switch (ch) {
              case 'a':
                  abbreviated = true;
                  break;
              case 'd':
                  seg_fault_on_exit = 1;
                  break;
              case 'k':
                  log_target = LOG_KLOG;
                  klog_set_level(6);
                  break;
              case '?':
              default:
                usage();
          }
      }
      argc -= optind;
      argv += optind;
  
      if (argc < 1) {
          usage();
      }
  
      rc = android_fork_execvp_ext(argc, &argv[0], &status, true,
                                   log_target, abbreviated);
      if (!rc) {
          if (WIFEXITED(status))
              rc = WEXITSTATUS(status);
          else
              rc = -ECHILD;
      }
  
      if (seg_fault_on_exit) {
          *(int *)status = 0;  // causes SIGSEGV with fault_address = status
      }
  
      return rc;
  }
  