/*----------------------------------------------------------------------* 
 *                                                                      * 
 * Description: Source du fichier exec. /equipe/sysadmin/bin/wtmpxcut   * 
 *              qui permet de reduire le fichier /var/adm/wtmpx en enle-* 
 *              vant toutes les entrees plus vieilles qu'une certaine   * 
 *              date specifiee en parametre. Si aucun parametre n'est   * 
 *              specifie, on utilise une valeur par defaut (DELAIS).    * 
 *                                                                      * 
 *----------------------------------------------------------------------*/ 
 
#include <stdio.h> 
#include <sys/types.h> 
#include <fcntl.h> 
#include <utmpx.h> 
#include <time.h> 
#include <errno.h> 
#include <unistd.h> 

#define ORIGFILE "/var/adm/wtmpx"
#define TEMPFILE "/export/local/sbin/wtmpx_temp"
#define DELFILE "/export/local/sbin/wtmpx_del"
 
#define DELAIS  (time_t) (45)                           /* in days */ 
 
int main(argc, argv) 
int argc; 
char **argv; 
{ 
  struct  utmpx wtmpx_rec; 
  int     old_fd, new_fd, del_fd; 
  int     wtmpx_rec_sz = sizeof(wtmpx_rec); 
  time_t  periode, temps_limite; 
  char garbage[80];
 
  if (argc > 1) 
      periode = (time_t) atoi(argv[1]); 
  else 
      periode = DELAIS; 
 
  /* 
  * Copie de /var/adm/wtmpx into /tmp/wtmpx 
  */ 
  putenv("IFS=' \t\n'");                        /* Securite */ 
  putenv("PATH=/usr/bin");                      /* Securite */ 
  sprintf(garbage,"cp %s %s", ORIGFILE, TEMPFILE);
  if (system(garbage) < 0) { 
    fprintf(stderr,"%s: Error in copying  %s into %s.\nBye.\n",argv[0],
		ORIGFILE, TEMPFILE); 
    exit(1); 
  } /* if */ 
 
  /* 
   *  Calcule du temps limite en time_t   
   */ 
  temps_limite = time(NULL) - (periode * 24 * 3600); 
  fprintf(stdout, 
  "\n%s: The date limit is %s\n", argv[0], asctime(localtime(&temps_limite))); 
 
  /* 
   *  Open the new file for writing
   */ 
  if ((new_fd = open(ORIGFILE, O_WRONLY | O_TRUNC)) < 0) { 
    fprintf(stderr, "%s: Error %d in writing %s .\nBye.\n", 
            argv[0], errno, ORIGFILE); 
    exit(1); 
  } /* if */ 

  /* 
   *  Open the del file for writing
   */ 
  if ((del_fd = open(DELFILE, O_WRONLY | O_TRUNC | O_CREAT )) < 0) { 
    fprintf(stderr, "%s: Error %d in writing %s.\nBye.\n", 
            argv[0], errno, DELFILE); 
    exit(1); 
  } /* if */ 
 
  /* 
   * Open the copy of wtmp for readonly
   */ 
  if ((old_fd = open(TEMPFILE, O_RDONLY)) < 0) { 
    fprintf(stderr, "%s: Error %d in opening %s.\nBye.\n", 
            argv[0], errno, TEMPFILE); 
    exit(1); 
  } /* if */ 
 
  /* 
   * En partant du debut du fichier, on compare les dates 
   * et si elles sont trop vieilles, on les oublies. 
   * Lorsqu'elles sont dans la periode, on les garde dans 
   * le fichier /var/adm/wtmpx. 
   */ 
  while (read(old_fd, &wtmpx_rec, wtmpx_rec_sz) == wtmpx_rec_sz) { 
    if (wtmpx_rec.ut_xtime >= temps_limite) { 
        if (write(new_fd, &wtmpx_rec, wtmpx_rec_sz) != wtmpx_rec_sz) { 
          fprintf(stderr, "%s: Error %d in writing the record.\nBye.",  
                  argv[0], errno); 
          exit(1); 
        } /* if */ 
    } /* if */ 
	else {
        if (write(del_fd, &wtmpx_rec, wtmpx_rec_sz) != wtmpx_rec_sz) { 
          fprintf(stderr, "%s: Error %d in writing the record.\nBye.",  
                  argv[0], errno); 
          exit(1); 
        } /* if */ 
	}
  } /* while */ 
 
  unlink (TEMPFILE);
  exit(0);                                      /* Nice Exit */
 
} /* main() */