tools/viconf.c

   1 /*
   2  * viconf.c
   3  *
   4  */
   5 #include <stdio.h>
   6 #include <unistd.h>
   7 #include <fcntl.h>
   8 #include <stdlib.h>
   9 #include <errno.h>
  10 #include <string.h>
  11 #include <limits.h>
  12 #include <signal.h>
  13 #include "config.h"
  14
  15
  16 /* wait.h is in /include on solaris, likely on other SYSV machines as well
  17  * but wait.h is normally in /include/sys on BSD boxen,
  18  * probably we should have an #ifdef SYSV?
  19  * -Dianora
  20  */
  21
  22 #ifdef SOL20
  23 #include <wait.h>
  24 #else
  25 #include <sys/wait.h>
  26 #endif
  27
  28 static int LockedFile(const char *filename);
  29 static char lockpath[PATH_MAX + 1];
  30
  31
  32 int main(int argc, char *argv[])
  33 {
  34   const char *ed, *p, *filename = CPATH;
  35
  36   if( chdir(DPATH) < 0 )
  37     {
  38       fprintf(stderr,"Cannot chdir to %s\n", DPATH);
  39       exit(errno);
  40     }
  41
  42   if((p = strrchr(argv[0], '/')) == NULL)
  43     p = argv[0];
  44   else
  45     p++;
  46 #ifdef KPATH
  47   if(strcmp(p, "viklines") == 0)
  48     filename = KPATH;
  49 #endif /* KPATH */
  50
  51   if(strcmp(p, "vimotd") == 0)
  52     filename = MPATH;
  53
  54   if(LockedFile(filename))
  55     {
  56       fprintf(stderr,"Can't lock %s\n", filename);
  57       exit(errno);
  58     }
  59
  60   /* ed config file */
  61   switch(fork())
  62     {
  63     case -1:
  64       fprintf(stderr, "error forking, %d\n", errno);
  65       exit(errno);
  66     case 0:             /* Child */
  67       if((ed = getenv("EDITOR")) == NULL)
  68         ed = "vi";
  69       execlp(ed, ed, filename, NULL);
  70       fprintf(stderr, "error running editor, %d\n", errno);
  71       exit(errno);
  72     default:
  73       wait(0);
  74     }
  75
  76   unlink(lockpath);
  77   return 0;
  78 }
  79
  80 /*
  81  * LockedFile() (copied from m_kline.c in ircd)
  82  * Determine if 'filename' is currently locked. If it is locked,
  83  * there should be a filename.lock file which contains the current
  84  * pid of the editing process. Make sure the pid is valid before
  85  * giving up.
  86  *
  87  * Return: 1 if locked
  88  *         -1 if couldn't unlock
  89  *         0 if was able to lock
  90  */
  91
  92
  93
  94 static int
  95 LockedFile(const char *filename)
  96
  97 {
  98
  99   char buffer[1024];
 100   FILE *fileptr;
 101   int killret;
 102   int fd;
 103
 104   if (!filename)
 105     return (0);
 106
 107   sprintf(lockpath, "%s.lock", filename);
 108
 109   if ((fileptr = fopen(lockpath, "r")) != NULL)
 110     {
 111       if (fgets(buffer, sizeof(buffer) - 1, fileptr))
 112         {
 113           /*
 114            * If it is a valid lockfile, 'buffer' should now
 115            * contain the pid number of the editing process.
 116            * Send the pid a SIGCHLD to see if it is a valid
 117            * pid - it could be a remnant left over from a
 118            * crashed editor or system reboot etc.
 119            */
 120
 121           killret = kill(atoi(buffer), SIGCHLD);
 122           if (killret == 0)
 123             {
 124               fclose(fileptr);
 125               return (1);
 126             }
 127
 128           /*
 129            * killret must be -1, which indicates an error (most
 130            * likely ESRCH - No such process), so it is ok to
 131            * proceed writing klines.
 132            */
 133         }
 134       fclose(fileptr);
 135     }
 136
 137   /*
 138    * Delete the outdated lock file
 139    */
 140   unlink(lockpath);
 141
 142   /* create exclusive lock */
 143   if((fd = open(lockpath, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
 144     {
 145       fprintf(stderr, "ircd config file locked\n");
 146       return (-1);
 147     }
 148
 149   fileptr = fdopen(fd,"w");
 150   fprintf(fileptr,"%d\n",(int)getpid());
 151   fclose(fileptr);
 152   return (0);
 153 } /* LockedFile() */