2.11BSD#431 - /usr/src/lib/libc/net/hosttable/gethostent.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)gethostent.c	5.3 (Berkeley) 3/9/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: #include <stdio.h>
  12: #include <sys/types.h>
  13: #include <sys/socket.h>
  14: #include <arpa/inet.h>
  15: #include <netdb.h>
  16: #include <ctype.h>
  17: #include <ndbm.h>
  18: 
  19: /*
  20:  * Internet version.
  21:  */
  22: #define MAXALIASES  20
  23: #define MAXADDRSIZE (sizeof (u_long))
  24: 
  25: static FILE *hostf = NULL;
  26: static char line[160+1];
  27: static char hostaddr[MAXADDRSIZE];
  28: static struct hostent host;
  29: static char *host_aliases[MAXALIASES];
  30: static char *host_addrs[] = {
  31:     hostaddr,
  32:     NULL
  33: };
  34: 
  35: /*
  36:  * The following is shared with gethostnamadr.c
  37:  */
  38: char    *_host_file = "/etc/hosts";
  39: int _host_stayopen;
  40: DBM *_host_db;  /* set by gethostbyname(), gethostbyaddr() */
  41: 
  42: static char *any();
  43: 
  44: sethostent(f)
  45:     int f;
  46: {
  47:     if (hostf != NULL)
  48:         rewind(hostf);
  49:     _host_stayopen |= f;
  50: }
  51: 
  52: endhostent()
  53: {
  54:     if (hostf) {
  55:         fclose(hostf);
  56:         hostf = NULL;
  57:     }
  58:     if (_host_db) {
  59:         dbm_close(_host_db);
  60:         _host_db = (DBM *)NULL;
  61:     }
  62:     _host_stayopen = 0;
  63: }
  64: 
  65: struct hostent *
  66: gethostent()
  67: {
  68:     char *p;
  69:     register char *cp, **q;
  70: 
  71:     if (hostf == NULL && (hostf = fopen(_host_file, "r" )) == NULL)
  72:         return (NULL);
  73: again:
  74:     if ((p = fgets(line, sizeof(line)-1, hostf)) == NULL)
  75:         return (NULL);
  76:     if (*p == '#')
  77:         goto again;
  78:     cp = any(p, "#\n");
  79:     if (cp == NULL)
  80:         goto again;
  81:     *cp = '\0';
  82:     cp = any(p, " \t");
  83:     if (cp == NULL)
  84:         goto again;
  85:     *cp++ = '\0';
  86:     /* THIS STUFF IS INTERNET SPECIFIC */
  87:     host.h_addr_list = host_addrs;
  88:     *((u_long *)host.h_addr) = inet_addr(p);
  89:     host.h_length = sizeof (u_long);
  90:     host.h_addrtype = AF_INET;
  91:     while (*cp == ' ' || *cp == '\t')
  92:         cp++;
  93:     host.h_name = cp;
  94:     q = host.h_aliases = host_aliases;
  95:     cp = any(cp, " \t");
  96:     if (cp != NULL)
  97:         *cp++ = '\0';
  98:     while (cp && *cp) {
  99:         if (*cp == ' ' || *cp == '\t') {
 100:             cp++;
 101:             continue;
 102:         }
 103:         if (q < &host_aliases[MAXALIASES - 1])
 104:             *q++ = cp;
 105:         cp = any(cp, " \t");
 106:         if (cp != NULL)
 107:             *cp++ = '\0';
 108:     }
 109:     *q = NULL;
 110:     return (&host);
 111: }
 112: 
 113: sethostfile(file)
 114:     char *file;
 115: {
 116:     _host_file = file;
 117: }
 118: 
 119: static char *
 120: any(cp, match)
 121:     register char *cp;
 122:     char *match;
 123: {
 124:     register char *mp, c;
 125: 
 126:     while (c = *cp) {
 127:         for (mp = match; *mp; mp++)
 128:             if (*mp == c)
 129:                 return (cp);
 130:         cp++;
 131:     }
 132:     return ((char *)0);
 133: }

Defined functions

Defined variables

Defined macros