LinuxReviws.org --get your your Linux knowledge
> Linux Reviews > Manual Pages (man) >

uname

print system information


  1. uname.1.man
  2. uname.2.man


1. uname.1.man

Manpage of UNAME

UNAME

Section: User Commands (1)
Updated: January 2012
Index Return to Main Contents
 

NAME

uname - print system information  

SYNOPSIS

uname [OPTION]...  

DESCRIPTION

Print certain system information. With no OPTION, same as -s.

-a, --all
print all information, in the following order, except omit -p and -i if unknown:
-s, --kernel-name
print the kernel name
-n, --nodename
print the network node hostname
-r, --kernel-release
print the kernel release
-v, --kernel-version
print the kernel version
-m, --machine
print the machine hardware name
-p, --processor
print the processor type or "unknown"
-i, --hardware-platform
print the hardware platform or "unknown"
-o, --operating-system
print the operating system
--help
display this help and exit
--version
output version information and exit
 

AUTHOR

Written by David MacKenzie.  

REPORTING BUGS

Report uname bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report uname translation bugs to <http://translationproject.org/team/>


Packaged by Gentoo (8.14 (p1))
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  

SEE ALSO

arch(1), uname(2)

The full documentation for uname is maintained as a Texinfo manual. If the info and uname programs are properly installed at your site, the command

info coreutils aquname invocationaq

should give you access to the complete manual.


 

Index

NAME
SYNOPSIS
DESCRIPTION
AUTHOR
REPORTING BUGS
SEE ALSO

This document was created by man2html using the manual pages.
Time: 17:32:54 GMT, October 23, 2013

2. uname.2.man

Manpage of UNAME

UNAME

Section: Linux Programmer's Manual (2)
Updated: 2008-12-03
Index Return to Main Contents
 

NAME

uname - get name and information about current kernel  

SYNOPSIS

#include <sys/utsname.h>

int uname(struct utsname *buf);  

DESCRIPTION

uname() returns system information in the structure pointed to by buf. The utsname struct is defined in <sys/utsname.h>:

struct utsname {
    char sysname[];    /* Operating system name (e.g., "Linux") */
    char nodename[];   /* Name within "some implementation-defined
                          network" */
    char release[];    /* OS release (e.g., "2.6.28") */
    char version[];    /* OS version */
    char machine[];    /* Hardware identifier */
#ifdef _GNU_SOURCE
    char domainname[]; /* NIS or YP domain name */
#endif
};

The length of the arrays in a struct utsname is unspecified (see NOTES); the fields are terminated by a null byte (aq\0aq).  

RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.  

ERRORS

EFAULT
buf is not valid.
 

CONFORMING TO

SVr4, POSIX.1-2001. There is no uname() call in 4.3BSD.

The domainname member (the NIS or YP domain name) is a GNU extension.  

NOTES

This is a system call, and the operating system presumably knows its name, release and version. It also knows what hardware it runs on. So, four of the fields of the struct are meaningful. On the other hand, the field nodename is meaningless: it gives the name of the present machine in some undefined network, but typically machines are in more than one network and have several names. Moreover, the kernel has no way of knowing about such things, so it has to be told what to answer here. The same holds for the additional domainname field.

To this end Linux uses the system calls sethostname(2) and setdomainname(2). Note that there is no standard that says that the hostname set by sethostname(2) is the same string as the nodename field of the struct returned by uname() (indeed, some systems allow a 256-byte hostname and an 8-byte nodename), but this is true on Linux. The same holds for setdomainname(2) and the domainname field.

The length of the fields in the struct varies. Some operating systems or libraries use a hardcoded 9 or 33 or 65 or 257. Other systems use SYS_NMLN or _SYS_NMLN or UTSLEN or _UTSNAME_LENGTH. Clearly, it is a bad idea to use any of these constants; just use sizeof(...). Often 257 is chosen in order to have room for an internet hostname.

Part of the utsname information is also accessible via /proc/sys/kernel/{ostype, hostname, osrelease, version, domainname}.  

Underlying kernel interface

Over time, increases in the size of the utsname structure have led to three successive versions of uname(): sys_olduname() (slot __NR_oldolduname), sys_uname() (slot __NR_olduname), and sys_newuname() (slot __NR_uname). The first one used length 9 for all fields; the second used 65; the third also uses 65 but adds the domainname field. The glibc uname() wrapper function hides these details from applications, invoking the most recent version of the system call provided by the kernel.  

SEE ALSO

uname(1), getdomainname(2), gethostname(2)  

COLOPHON

This page is part of release 3.32 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/.


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
CONFORMING TO
NOTES
Underlying kernel interface
SEE ALSO
COLOPHON

This document was created by man2html using the manual pages.
Time: 17:32:54 GMT, October 23, 2013

cs - ENGLISH - ENGLISH - ENGLISH - ENGLISH - ja - pl - ENGLISH

Meet new people