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 #ifndef lint
8 static char sccsid[] = "@(#)gethostent.c	5.2 (Berkeley) 09/10/85";
9 #endif not lint
10 
11 #include <stdio.h>
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <netdb.h>
15 #include <ctype.h>
16 #include <ndbm.h>
17 
18 /*
19  * Internet version.
20  */
21 #define	MAXALIASES	35
22 #define	MAXADDRSIZE	14
23 
24 static FILE *hostf = NULL;
25 static char line[BUFSIZ+1];
26 static char hostaddr[MAXADDRSIZE];
27 static struct hostent host;
28 static char *host_aliases[MAXALIASES];
29 static char *host_addrs[] = {
30 	hostaddr,
31 	NULL
32 };
33 
34 /*
35  * The following is shared with gethostnamadr.c
36  */
37 char	*_host_file = "/etc/hosts";
38 int	_host_stayopen;
39 DBM	*_host_db;	/* set by gethostbyname(), gethostbyaddr() */
40 
41 static char *any();
42 
43 sethostent(f)
44 	int f;
45 {
46 	if (hostf != NULL)
47 		rewind(hostf);
48 	_host_stayopen |= f;
49 }
50 
51 endhostent()
52 {
53 	if (hostf) {
54 		fclose(hostf);
55 		hostf = NULL;
56 	}
57 	if (_host_db) {
58 		dbm_close(_host_db);
59 		_host_db = (DBM *)NULL;
60 	}
61 	_host_stayopen = 0;
62 }
63 
64 struct hostent *
65 gethostent()
66 {
67 	char *p;
68 	register char *cp, **q;
69 
70 	if (hostf == NULL && (hostf = fopen(_host_file, "r" )) == NULL)
71 		return (NULL);
72 again:
73 	if ((p = fgets(line, BUFSIZ, hostf)) == NULL)
74 		return (NULL);
75 	if (*p == '#')
76 		goto again;
77 	cp = any(p, "#\n");
78 	if (cp == NULL)
79 		goto again;
80 	*cp = '\0';
81 	cp = any(p, " \t");
82 	if (cp == NULL)
83 		goto again;
84 	*cp++ = '\0';
85 	/* THIS STUFF IS INTERNET SPECIFIC */
86 	host.h_addr_list = host_addrs;
87 	*((u_long *)host.h_addr) = inet_addr(p);
88 	host.h_length = sizeof (u_long);
89 	host.h_addrtype = AF_INET;
90 	while (*cp == ' ' || *cp == '\t')
91 		cp++;
92 	host.h_name = cp;
93 	q = host.h_aliases = host_aliases;
94 	cp = any(cp, " \t");
95 	if (cp != NULL)
96 		*cp++ = '\0';
97 	while (cp && *cp) {
98 		if (*cp == ' ' || *cp == '\t') {
99 			cp++;
100 			continue;
101 		}
102 		if (q < &host_aliases[MAXALIASES - 1])
103 			*q++ = cp;
104 		cp = any(cp, " \t");
105 		if (cp != NULL)
106 			*cp++ = '\0';
107 	}
108 	*q = NULL;
109 	return (&host);
110 }
111 
112 sethostfile(file)
113 	char *file;
114 {
115 	_host_file = file;
116 }
117 
118 static char *
119 any(cp, match)
120 	register char *cp;
121 	char *match;
122 {
123 	register char *mp, c;
124 
125 	while (c = *cp) {
126 		for (mp = match; *mp; mp++)
127 			if (*mp == c)
128 				return (cp);
129 		cp++;
130 	}
131 	return ((char *)0);
132 }
133