4.4BSD/usr/src/kerberosIV/krb/get_phost.c

/*
 * $Source: /usr/src/kerberosIV/krb/RCS/get_phost.c,v $
 * $Author: kfall $
 *
 * Copyright 1988 by the Massachusetts Institute of Technology.
 *
 * For copying and distribution information, please see the file
 * <mit-copyright.h>.
 */

#ifndef lint
static char *rcsid_phost_c =
"$Header: /usr/src/kerberosIV/krb/RCS/get_phost.c,v 4.7 90/06/25 20:57:57 kfall Exp $";
#endif /* lint */

#include <mit-copyright.h>
#include <stdio.h>
#include <ctype.h>
#include <netdb.h>

char *index();

/*
 * This routine takes an alias for a host name and returns the first
 * field, lower case, of its domain name.  For example, if "menel" is
 * an alias for host officially named "menelaus" (in /etc/hosts), for
 * the host whose official name is "MENELAUS.MIT.EDU", the name "menelaus"
 * is returned.
 *
 * This is done for historical Athena reasons: the Kerberos name of
 * rcmd servers (rlogin, rsh, rcp) is of the form "rcmd.host@realm"
 * where "host"is the lowercase for of the host name ("menelaus").
 * This should go away: the instance should be the domain name
 * (MENELAUS.MIT.EDU).  But for now we need this routine...
 *
 * A pointer to the name is returned, if found, otherwise a pointer
 * to the original "alias" argument is returned.
 */

char * krb_get_phost(alias)
    char *alias;
{
    struct hostent *h;
    char *phost = alias;
    if ((h=gethostbyname(alias)) != (struct hostent *)NULL ) {
        char *p = index( h->h_name, '.' );
        if (p)
            *p = NULL;
        p = phost = h->h_name;
        do {
            if (isupper(*p)) *p=tolower(*p);
        } while (*p++);
    }
    return(phost);
}