On Wed, 28 Jun 2000, Rick Parker wrote:
> How would I change the hostid for a Linux system?
>
For single process or completely? There is a solution
attached for both, or change ethernet card :)
> Do you know if it is the same with a SUN system?
>
Gosh I dont remember how to do it offially with
SUN, but as an ELF system I would expect that
attached tools work fine.
:-) riku
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/*
* $Id: hostid.c,v 1.1 1999/03/07 18:10:18 mesrik Exp $
*/
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/utsname.h>
int main(int argc, char *argv[]) {
struct utsname u;
char *p;
unsigned id;
if (p = strrchr (*argv, '/'))
p++;
else
p = *argv;
uname(&u);
switch (argc) {
case 2: if (sethostid((int)strtol(*++argv,NULL,0)))
perror(p);
break;
case 1: if (id = gethostid())
printf ("%s %s hostid is %u (0x%x)\n",
u.sysname, u.nodename, id, id);
else
printf ("%s %s hostid is unset%s\n",
u.sysname, u.nodename, !geteuid() ? "" :
" or you haven't got permission to read it");
break;
default: printf ("Usage: %s [hostid value to set]\n",p);
}
return 0;
}
/* eof */
/*
* $Id: fakeid.c,v 1.2 1999/08/24 15:17:18 mesrik Exp $
*
* Linux, SunOS usage: # make hostid
* # ./hostid
* # gcc -shared fakeid.c -o fakeid.so
* # HOSTID="0xbadbeef" LD_PRELOAD=./fakeid.so ./hostid
*
*
* HP-UX usage: # make hostid
* # ./hostid
* # gcc -fPIC -shared -Wl,-E,-b fakeid.c -o fakeid.sl
*
* Dunno yet how to do preload on HP-UX :/
*
*/
#include <time.h>
#include <limits.h>
#include <stdlib.h>
#include <unistd.h>
long int gethostid(void) {
static unsigned int id = 0;
char *nptr;
if ((nptr = getenv("HOSTID"))) {
return strtol(nptr,NULL,0);
} else {
if (!id) {
srand(getpid() * time(0));
id = 1+(int)(((float)(UINT_MAX))*rand()/(UINT_MAX+1.0));
}
return id;
}
}
/* eof */
