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static char rcsid[] = "$Id: host.c,v 1.12 1995/02/04 01:37:53 hardy Exp $";
/*
* host.c - Retrieves full DNS name of the current host
*
* Darren Hardy, hardy@cs.colorado.edu, April 1994
*
* ----------------------------------------------------------------------
* Copyright (c) 1994, 1995. All rights reserved.
*
* Mic Bowman of Transarc Corporation.
* Peter Danzig of the University of Southern California.
* Darren R. Hardy of the University of Colorado at Boulder.
* Udi Manber of the University of Arizona.
* Michael F. Schwartz of the University of Colorado at Boulder.
*
* This copyright notice applies to all code in Harvest other than
* subsystems developed elsewhere, which contain other copyright notices
* in their source text.
*
* The Harvest software was developed by the Internet Research Task
* Force Research Group on Resource Discovery (IRTF-RD). The Harvest
* software may be used for academic, research, government, and internal
* business purposes without charge. If you wish to sell or distribute
* the Harvest software to commercial clients or partners, you must
* license the software. See
* http://harvest.cs.colorado.edu/harvest/copyright,licensing.html#licensing.
*
* The Harvest software is provided ``as is'', without express or
* implied warranty, and with no support nor obligation to assist in its
* use, correction, modification or enhancement. We assume no liability
* with respect to the infringement of copyrights, trade secrets, or any
* patents, and are not responsible for consequential damages. Proper
* use of the Harvest software is entirely the responsibility of the user.
*
* For those who are using Harvest for non-commercial purposes, you may
* make derivative works, subject to the following constraints:
*
* - You must include the above copyright notice and these accompanying
* paragraphs in all forms of derivative works, and any documentation
* and other materials related to such distribution and use acknowledge
* that the software was developed at the above institutions.
*
* - You must notify IRTF-RD regarding your distribution of the
* derivative work.
*
* - You must clearly notify users that your are distributing a modified
* version and not the original Harvest software.
*
* - Any derivative product is also subject to the restrictions of the
* copyright, including distribution and use limitations.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include <ctype.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include "util.h"
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 256
#endif
/*
* getfullhostname() - Returns the fully qualified name of the current
* host, or NULL on error. Pointer is only valid until the next call
* to the gethost*() functions.
*/
char *getfullhostname()
{
struct hostent *hp;
char buf[MAXHOSTNAMELEN + 1];
extern int gethostname(); /* UNIX system call */
if (gethostname(buf, MAXHOSTNAMELEN) < 0)
return (NULL);
if ((hp = gethostbyname(buf)) == NULL)
return (NULL);
return (hp->h_name);
}
/*
* getmylogin() - Returns the login for the pid of the current process,
* or "nobody" if there is not login associated with the pid of the
* current process. Intended to be a replacement for braindead getlogin(3).
*/
char *getmylogin()
{
static char *nobody_str = "nobody";
uid_t myuid = getuid();
struct passwd *pwp;
pwp = getpwuid(myuid);
if (pwp == NULL || pwp->pw_name == NULL)
return (nobody_str);
return (pwp->pw_name);
}
/*
* getrealhost() - Returns the real fully qualified name of the given
* host or IP number, or NULL on error.
*/
char *getrealhost(s)
char *s;
{
char *q;
struct hostent *hp;
int is_octet = 1, ndots = 0;
unsigned int addr = 0;
if (s == NULL || *s == '\0')
return (NULL);
for (q = s; *q; q++) {
if (*q == '.') {
ndots++;
continue;
} else if (!isdigit(*q)) { /* [^0-9] is a name */
is_octet = 0;
break;
}
}
if (ndots != 3)
is_octet = 0;
if (is_octet) {
addr = inet_addr(s);
hp = gethostbyaddr((char *) &addr, sizeof(unsigned int), AF_INET);
} else {
hp = gethostbyname(s);
}
return (hp != NULL ? strdup(hp->h_name) : NULL);
}
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