Visit The New, Modern Unix Linux Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #539
Difficulty: Medium
In C, int x; creates an integer variable associated with the identifier x initialized to one .
True or False?
Linux & Unix Commands - Search Man Pages

makedev(3) [freebsd man page]

MAKEDEV(3)						   BSD Library Functions Manual 						MAKEDEV(3)

NAME
makedev, major, minor -- device number conversion SYNOPSIS
#include <sys/types.h> dev_t makedev(int major, int minor); int major(dev_t dev); int minor(dev_t dev); DESCRIPTION
The makedev() macro allows a unique device number to be generated based on its major and minor number. The major() and minor() macros can be used to obtain the original numbers from the device number dev. In previous implementations of FreeBSD all block and character devices were uniquely identified by a pair of major and minor numbers. The major number referred to a certain device class (e.g. disks, TTYs) while the minor number identified an instance within the device class. Later versions of FreeBSD automatically generate a unique device number for each character device visible in /dev/. These numbers are not divided in device classes. On FreeBSD these macros are only used by utilities that need to exchange numbers with other operating systems that may use different encod- ings for dev_t, but also applications that present these numbers to the user in a more conventional way. RETURN VALUES
The major() macro returns a device major number that has a value between 0 and 255. The minor() macro returns a device minor number whose value can span the complete range of an int. SEE ALSO
mknod(2), devname(3), devfs(5) BSD
September 28, 2008 BSD

Check Out this Related Man Page

MAKEDEV(3)						     Linux Programmer's Manual							MAKEDEV(3)

NAME
makedev, major, minor - manage a device number SYNOPSIS
#define _BSD_SOURCE #include <sys/types.h> dev_t makedev(int maj, int min); int major(dev_t dev); int minor(dev_t dev); DESCRIPTION
A device ID consists of two parts: a major ID, identifying the class of the device, and a minor ID, identifying a specific instance of a device in that class. A device ID is represented using the type dev_t. Given major and minor device IDs, makedev() combines these to produce a device ID, returned as the function result. This device ID can be given to mknod(2), for example. The major() and minor() functions perform the converse task: given a device ID, they return, respectively, the major and minor components. These macros can be useful to, for example, decompose the device IDs in the structure returned by stat(2). CONFORMING TO
The makedev() major() and minor() functions are not specified in POSIX.1, but are present on many other systems. NOTES
These interfaces are defined as macros. Since glibc 2.3.3, they have been aliases for three GNU-specific functions: gnu_dev_makedev(3), gnu_dev_major(3), and gnu_dev_minor(3). The latter names are exported, but the traditional names are more portable. SEE ALSO
mknod(2), stat(2) 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 2008-12-01 MAKEDEV(3)

15 More Discussions You Might Find Interesting

1. Solaris

major & minor number

Hi Can anyone tell me what is major number and minor number in the mknod command. Also what these numbers mean. I have gone through the man pages but still I couldn't understand. Regards (3 Replies)
Discussion started by: RajaRC
3 Replies

2. UNIX for Dummies Questions & Answers

message

Hello I installed solaris 9, but when I reboot the box, I got this message WARNING:add_spec:No major number for mpt WARNING:add_spec:No major number for mpt WARNING:add_spec:No major number for mpt WARNING:add_spec:No major number for mpt WARNING:add_spec:No major number for mpt ... (2 Replies)
Discussion started by: lo-lp-kl
2 Replies

3. HP-UX

recreating /dev/null

Something (I'm still trying to find out what) has clobbered our /dev/null and made it into an ordinary file. I know I need to recreate it with mknod, but I'm unsure what the major and minor device numbers should be - I know enough to know that they vary on different systems and I've seen 1 3, 2 2,... (4 Replies)
Discussion started by: pblake1
4 Replies

4. UNIX for Dummies Questions & Answers

differentiate between a file and a device

sorry probably a beginner question but i was just wondering how unix does this as device are treated as files? (6 Replies)
Discussion started by: keith_hampson
6 Replies

5. Shell Programming and Scripting

sort major.minor.release_build_x

would like to order this input based on major.minor.release AND build number Label abc_def_0.0.3_build_999 2008/08/01 'Created by me.' Label abc_def_0.0.9_build_1000 2008/08/01 'Created by me.' Label abc_def_9.0.9_build_10001 2008/08/01 'Created by me.' Label abc_def_10.9.100_build_2... (4 Replies)
Discussion started by: gurpal2000
4 Replies

6. Programming

which head file for major and minor function?

#include <sys/types.h> #include <sys/stat.h> #include <sys/termios.h> #include <stdio.h> #include <stdlib.h> #include <stddef.h> #include <string.h> #include <unistd.h> #include <signal.h> #include <sys/mkdev.h> int main(int argc, char *argv) { int i; struct stat buf; ... (4 Replies)
Discussion started by: konvalo
4 Replies

7. AIX

major no

hi what is meant by major no in vg what is meant by concurrent vg i cant understand these two things (3 Replies)
Discussion started by: senmak
3 Replies

8. UNIX for Dummies Questions & Answers

Getting unique list of numbers using grep

Hi, I am going to fetch a list of numbers that starts with "0032" from a file with a format like the given below: " 0032459999 0032458888 0032457777 0032451111 0032452222 0032453333 0032459999 0032458888 0032457777 0032451111 0032452222 0032453333 " I want to get a unique... (6 Replies)
Discussion started by: tinku
6 Replies

9. Shell Programming and Scripting

How to filter out major and minor?

Hi, I have line like this : proj_name/module/trunk/module_1_0 where the first "1" refers to major version and second "0" refers to minor version. any AWK or command like that so that I can filter out the major and minor ? like major= command | input line minor= command |... (4 Replies)
Discussion started by: bhaskar_m
4 Replies

10. What is on Your Mind?

Favorite UNIX-like OS for laptop

First, a hello to all of you out there. Quick introduction since I'm new here before I ask my question. I'm a Computer Science major who has an unnatural love of operating systems. :) In fact, I'm looking on building a new computer that will have enough RAM to let me have some fun with several VMs... (7 Replies)
Discussion started by: ViperChief
7 Replies

11. UNIX for Dummies Questions & Answers

Which kind of UNIX to major investment banks use?

Hi, I would like to know what kind of UNIX major investment banks tend to use? I want to try to get a job with one of these places. By major, I mean big companies like Citigroup, JP Morgan Chase, Morgan Stanley, etc. Thanks. (5 Replies)
Discussion started by: rubrubber
5 Replies

12. AIX

VG major number in HACMP

HI All, I would like to know is it compulsory to keep major number of shared VG's on cluster nodes to be same..? I have come across a situation where on one node major number of shared vg is the major number of altinst_rootvg on other node..how to overcome this situation..? shan (3 Replies)
Discussion started by: to_bsr
3 Replies

13. Shell Programming and Scripting

How to generate 10.000 unique numbers?

hello, does anybody can give me a hint on how to generate a lot of numbers which are not identically via scripting etc? (7 Replies)
Discussion started by: xrays
7 Replies

14. Shell Programming and Scripting

insert one line inbetween file with use of numbers

Hi All, I have one file name called test.txt and its having numbers inside the file.I need to identified next available number with use of unix shell scipt and have to update next available number with use of unix shell script. Example:- cat test.txt 5001 5002 5003 5005 7000 7001 ... (5 Replies)
Discussion started by: susindram
5 Replies

15. Programming

GCC: General Macro for BSD

Is there a universal macro for any BSD system. I am currently on FreeBSD where __FreeBSD__ is defined. It looks like on NetBSD systems __NetBSD__ is defined. I have tried using __BSD__ but doesn't appear to exists. Is there a universal way of testing if you are using any BSD system with GCC?... (6 Replies)
Discussion started by: AntumDeluge
6 Replies

Featured Tech Videos