GETHOSTID(2) Linux Programmer's Manual GETHOSTID(2)NAME
gethostid, sethostid - get or set the unique identifier of the current host
SYNOPSIS
#include <unistd.h>
long gethostid(void);
int sethostid(long hostid);
DESCRIPTION
Get or set a unique 32-bit identifier for the current machine. The 32-bit identifier is intended to be unique among all UNIX systems in
existence. This normally resembles the Internet address for the local machine, as returned by gethostbyname(3), and thus usually never
needs to be set.
The sethostid call is restricted to the superuser.
The hostid argument is stored in the file /etc/hostid.
RETURN VALUE
gethostid returns the 32-bit identifier for the current host as set by sethostid(2).
CONFORMING TO
4.2BSD. These functions were dropped in 4.4BSD. POSIX.1 does not define these functions, but ISO/IEC 9945-1:1990 mentions them in
B.4.4.1. SVr4 includes gethostid but not sethostid.
FILES
/etc/hostid
SEE ALSO hostid(1), gethostbyname(3)Linux 0.99.13 1993-11-29 GETHOSTID(2)
Check Out this Related Man Page
GETHOSTID(3) Linux Programmer's Manual GETHOSTID(3)NAME
gethostid, sethostid - get or set the unique identifier of the current host
SYNOPSIS
#include <unistd.h>
long gethostid(void);
int sethostid(long hostid);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
sethostid(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
DESCRIPTION
gethostid() and sethostid() respectively get or set a unique 32-bit identifier for the current machine. The 32-bit identifier is intended
to be unique among all Unix systems in existence. This normally resembles the Internet address for the local machine, as returned by geth-
ostbyname(3), and thus usually never needs to be set.
The sethostid() call is restricted to the superuser.
RETURN VALUE
gethostid() returns the 32-bit identifier for the current host as set by sethostid().
On success, sethostid() returns 0; on error, -1 is returned, and errno is set to indicate the error.
ERRORS
sethostid() can fail with the following errors:
EACCES The caller did not have permission to write to the file used to store the host ID.
EPERM The calling process's effective user or group ID is not the same as its corresponding real ID.
CONFORMING TO
4.2BSD; these functions were dropped in 4.4BSD. SVr4 includes gethostid() but not sethostid(). POSIX.1-2001 specifies gethostid() but not
sethostid().
NOTES
In the glibc implementation, the hostid is stored in the file /etc/hostid. (In glibc versions before 2.2, the file /var/adm/hostid was
used.)
In the glibc implementation, if gethostid() cannot open the file containing the host ID, then it obtains the hostname using gethostname(2),
passes that hostname to gethostbyname_r(3) in order to obtain the host's IPv4 address, and returns a value obtained by bit-twiddling the
IPv4 address. (This value may not be unique.)
BUGS
It is impossible to ensure that the identifier is globally unique.
SEE ALSO hostid(1), gethostbyname(3)COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2009-01-13 GETHOSTID(3)
Hello folks,
I've got a problem I've found to be quite difficult to solve. Recently I bought an old UNIX machine from the late eighties, a DIAB1100 with a Motorola 68K processor. I've used Linux for a while now, so I know the basics of that OS and thought it would be interesting to see a real... (8 Replies)
Hi,
How do you actually create a unique ID on a distributed system. I looked at gethostid but the man page says that its not guaranteed to be unique. Also using the IP address does not seem to be a feasible solution. Is there a function call or mechanism by which this is possible when even the... (4 Replies)
Hi,
I am using 32 bit machine, and I want to compile 64 bit application on 32-bit machine.
So please tell me is it possible or not?
Regards
Mandar (7 Replies)
Hello Everybody
I would like to know that I have configure the OS & other application on the SunFire V440 server
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Hi there,
Honestly i'm not much of a code guy but i found some short piece of code over the net which i need to compile in my Solaris machine (in order to change my hostid).
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I've searched the UNIX forum looking for a simple procedure how to change\control my Solaris server hostid.
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There is no /etc/hostid file.
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#... (0 Replies)
Hi, i tried to do this script:
Generate a "unique" 6-digit hexadecimal identifier for your computer. Do not use the flawed hostid command. Hint: md5sum /etc/passwd, then select the first 6 digits of output.
Fom 0 to 9 and from a to f
#!/bin/bash
clear
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I have IBM Z-Linux machine as well as RedHat Linux.
Where do I see that the particular machine is z-Linux?
below output from zlinux.
$ uname -a
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below output from redhat.
$ uname -a... (3 Replies)