text: /*
   * MIT License
   *
   * Copyright (c) 2019 Jianhui Zhao <zhaojh329@gmail.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <time.h>
  #include <stdio.h>
  #include <stdarg.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <string.h>
  #include <stdbool.h>
  
  #include "log.h"
  
  static int log_threshold = LOG_DEBUG;
  static bool log_initialized;
  static const char *ident;
  
  void (*log_write)(int priority, const char *fmt, va_list ap);
  
  static const char *log_ident()
  {
      FILE *self;
      static char line[64];
      char *p = NULL;
      char *sbuf;
  
      if ((self = fopen("/proc/self/status", "r")) != NULL) {
          while (fgets(line, sizeof(line), self)) {
              if (!strncmp(line, "Name:", 5)) {
                  strtok_r(line, "\t\n", &sbuf);
                  p = strtok_r(NULL, "\t\n", &sbuf);
                  break;
              }
          }
          fclose(self);
      }
  
      return p;
  }
  
  static inline void log_write_stdout(int priority, const char *fmt, va_list ap)
  {
      time_t now;
      struct tm tm;
      char buf[32];
  
      now = time(NULL);
      localtime_r(&now, &tm);
      strftime(buf, sizeof(buf), "%Y/%m/%d %H:%M:%S", &tm);
  
      fprintf(stderr, "%s ", buf);
      vfprintf(stderr, fmt, ap);
  }
  
  static inline void log_write_syslog(int priority, const char *fmt, va_list ap)
  {
      vsyslog(priority, fmt, ap);
  }
  
  static inline void log_init()
  {
      if (log_initialized)
          return;
  
      ident = log_ident();
  
      if (isatty(STDOUT_FILENO)) {
          log_write = log_write_stdout;
      } else {
          log_write = log_write_syslog;
  
          openlog(ident, 0, LOG_DAEMON);
      }
  
      log_initialized = true;
  }
  
  
  void uh_log_threshold(int threshold)
  {
      log_threshold = threshold;
  }
  
  int uh_log_get_threshold()
  {
      return log_threshold;
  }
  
  void uh_log_close()
  {
      if (!log_initialized)
          return;
  
      closelog();
  
      log_initialized = 0;
  }
  
  void __uh_log(const char *filename, int line, int priority, const char *fmt, ...)
  {
      static char new_fmt[256];
      va_list ap;
  
      if (priority > log_threshold)
          return;
  
      log_init();
  
      snprintf(new_fmt, sizeof(new_fmt), "(%s:%d) %s", filename, line, fmt);
  
      va_start(ap, fmt);
      log_write(priority, new_fmt, ap);
      va_end(ap);
  }
  
  