tools/viconf.c

   1 /*
   2  * viconf.c
   3  *
   4  * $Id: viconf.c 13238 2002-11-29 17:28:30Z leeh $
   5  */
   6 #include <stdio.h>
   7 #include <unistd.h>
   8 #include <fcntl.h>
   9 #include <stdlib.h>
  10 #include <errno.h>
  11 #include <string.h>
  12 #include <limits.h>
  13 #include <signal.h>
  14 #include "config.h"
  15
  16
  17 /* wait.h is in /include on solaris, likely on other SYSV machines as well
  18  * but wait.h is normally in /include/sys on BSD boxen,
  19  * probably we should have an #ifdef SYSV?
  20  * -Dianora
  21  */
  22
  23 #ifdef SOL20
  24 #include <wait.h>
  25 #else
  26 #include <sys/wait.h>
  27 #endif
  28
  29 static int LockedFile(const char *filename);
  30 static char lockpath[PATH_MAX + 1];
  31
  32
  33 int main(int argc, char *argv[])
  34 {
  35   const char *ed, *p, *filename = CPATH;
  36
  37   if( chdir(DPATH) < 0 )
  38     {
  39       fprintf(stderr,"Cannot chdir to %s\n", DPATH);
  40       exit(errno);
  41     }
  42
  43   if((p = strrchr(argv[0], '/')) == NULL)
  44     p = argv[0];
  45   else
  46     p++;
  47 #ifdef KPATH
  48   if(strcmp(p, "viklines") == 0)
  49     filename = KPATH;
  50 #endif /* KPATH */
  51
  52   if(strcmp(p, "vimotd") == 0)
  53     filename = MPATH;
  54
  55   if(LockedFile(filename))
  56     {
  57       fprintf(stderr,"Can't lock %s\n", filename);
  58       exit(errno);
  59     }
  60
  61   /* ed config file */
  62   switch(fork())
  63     {
  64     case -1:
  65       fprintf(stderr, "error forking, %d\n", errno);
  66       exit(errno);
  67     case 0:             /* Child */
  68       if((ed = getenv("EDITOR")) == NULL)
  69         ed = "vi";
  70       execlp(ed, ed, filename, NULL);
  71       fprintf(stderr, "error running editor, %d\n", errno);
  72       exit(errno);
  73     default:
  74       wait(0);
  75     }
  76
  77   unlink(lockpath);
  78   return 0;
  79 }
  80
  81 /*
  82  * LockedFile() (copied from m_kline.c in ircd)
  83  * Determine if 'filename' is currently locked. If it is locked,
  84  * there should be a filename.lock file which contains the current
  85  * pid of the editing process. Make sure the pid is valid before
  86  * giving up.
  87  *
  88  * Return: 1 if locked
  89  *         -1 if couldn't unlock
  90  *         0 if was able to lock
  91  */
  92
  93
  94
  95 static int
  96 LockedFile(const char *filename)
  97
  98 {
  99
 100   char buffer[1024];
 101   FILE *fileptr;
 102   int killret;
 103   int fd;
 104
 105   if (!filename)
 106     return (0);
 107
 108   sprintf(lockpath, "%s.lock", filename);
 109
 110   if ((fileptr = fopen(lockpath, "r")) != NULL)
 111     {
 112       if (fgets(buffer, sizeof(buffer) - 1, fileptr))
 113         {
 114           /*
 115            * If it is a valid lockfile, 'buffer' should now
 116            * contain the pid number of the editing process.
 117            * Send the pid a SIGCHLD to see if it is a valid
 118            * pid - it could be a remnant left over from a
 119            * crashed editor or system reboot etc.
 120            */
 121
 122           killret = kill(atoi(buffer), SIGCHLD);
 123           if (killret == 0)
 124             {
 125               fclose(fileptr);
 126               return (1);
 127             }
 128
 129           /*
 130            * killret must be -1, which indicates an error (most
 131            * likely ESRCH - No such process), so it is ok to
 132            * proceed writing klines.
 133            */
 134         }
 135       fclose(fileptr);
 136     }
 137
 138   /*
 139    * Delete the outdated lock file
 140    */
 141   unlink(lockpath);
 142
 143   /* create exclusive lock */
 144   if((fd = open(lockpath, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
 145     {
 146       fprintf(stderr, "ircd config file locked\n");
 147       return (-1);
 148     }
 149
 150   fileptr = fdopen(fd,"w");
 151   fprintf(fileptr,"%d\n",(int)getpid());
 152   fclose(fileptr);
 153   return (0);
 154 } /* LockedFile() */