tools/viconf.c

   1 /*
   2  * viconf.c
   3  *
   4  * $Id: viconf.c 6 2005-09-10 01:02:21Z nenolod $
   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
  48   if(strcmp(p, "vimotd") == 0)
  49     filename = MPATH;
  50
  51   if(LockedFile(filename))
  52     {
  53       fprintf(stderr,"Can't lock %s\n", filename);
  54       exit(errno);
  55     }
  56
  57   /* ed config file */
  58   switch(fork())
  59     {
  60     case -1:
  61       fprintf(stderr, "error forking, %d\n", errno);
  62       exit(errno);
  63     case 0:             /* Child */
  64       if((ed = getenv("EDITOR")) == NULL)
  65         ed = "vi";
  66       execlp(ed, ed, filename, NULL);
  67       fprintf(stderr, "error running editor, %d\n", errno);
  68       exit(errno);
  69     default:
  70       wait(0);
  71     }
  72
  73   unlink(lockpath);
  74   return 0;
  75 }
  76
  77 /*
  78  * LockedFile() (copied from m_kline.c in ircd)
  79  * Determine if 'filename' is currently locked. If it is locked,
  80  * there should be a filename.lock file which contains the current
  81  * pid of the editing process. Make sure the pid is valid before
  82  * giving up.
  83  *
  84  * Return: 1 if locked
  85  *         -1 if couldn't unlock
  86  *         0 if was able to lock
  87  */
  88
  89
  90
  91 static int
  92 LockedFile(const char *filename)
  93
  94 {
  95
  96   char buffer[1024];
  97   FILE *fileptr;
  98   int killret;
  99   int fd;
 100
 101   if (!filename)
 102     return (0);
 103
 104   sprintf(lockpath, "%s.lock", filename);
 105
 106   if ((fileptr = fopen(lockpath, "r")) != NULL)
 107     {
 108       if (fgets(buffer, sizeof(buffer) - 1, fileptr))
 109         {
 110           /*
 111            * If it is a valid lockfile, 'buffer' should now
 112            * contain the pid number of the editing process.
 113            * Send the pid a SIGCHLD to see if it is a valid
 114            * pid - it could be a remnant left over from a
 115            * crashed editor or system reboot etc.
 116            */
 117
 118           killret = kill(atoi(buffer), SIGCHLD);
 119           if (killret == 0)
 120             {
 121               fclose(fileptr);
 122               return (1);
 123             }
 124
 125           /*
 126            * killret must be -1, which indicates an error (most
 127            * likely ESRCH - No such process), so it is ok to
 128            * proceed writing klines.
 129            */
 130         }
 131       fclose(fileptr);
 132     }
 133
 134   /*
 135    * Delete the outdated lock file
 136    */
 137   unlink(lockpath);
 138
 139   /* create exclusive lock */
 140   if((fd = open(lockpath, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
 141     {
 142       fprintf(stderr, "ircd config file locked\n");
 143       return (-1);
 144     }
 145
 146   fileptr = fdopen(fd,"w");
 147   fprintf(fileptr,"%d\n",(int)getpid());
 148   fclose(fileptr);
 149   return (0);
 150 } /* LockedFile() */