Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #592
Difficulty: Medium
Suppose we want to sort a huge collection of 1 trillion, 10^12, elements. Doing so with Selection Sort or Insertion Sort would require about n^2 = (10^12)^2 = 10^24 or 1 sextillion comparisons.
True or False?
Linux & Unix Commands - Search Man Pages

ieee80211_generic_frame_duration(9) [centos man page]

IEEE80211_GENERIC_FR(9) 				  The basic mac80211 driver inte				   IEEE80211_GENERIC_FR(9)

NAME
ieee80211_generic_frame_duration - Calculate the duration field for a frame SYNOPSIS
__le16 ieee80211_generic_frame_duration(struct ieee80211_hw * hw, struct ieee80211_vif * vif, enum ieee80211_band band, size_t frame_len, struct ieee80211_rate * rate); ARGUMENTS
hw pointer obtained from ieee80211_alloc_hw. vif struct ieee80211_vif pointer from the add_interface callback. band the band to calculate the frame duration on frame_len the length of the frame. rate the rate at which the frame is going to be transmitted. DESCRIPTION
Calculate the duration field of some generic frame, given its length and transmission rate (in 100kbps). RETURN
The duration. AUTHOR
Johannes Berg <johannes@sipsolutions.net> Author. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 IEEE80211_GENERIC_FR(9)

Check Out this Related Man Page

ENUM 
MAC80211_RATE_C(9) The basic mac80211 driver inte ENUM MAC80211_RATE_C(9) NAME
enum_mac80211_rate_control_flags - per-rate flags set by the Rate Control algorithm. SYNOPSIS
enum mac80211_rate_control_flags { IEEE80211_TX_RC_USE_RTS_CTS, IEEE80211_TX_RC_USE_CTS_PROTECT, IEEE80211_TX_RC_USE_SHORT_PREAMBLE, IEEE80211_TX_RC_MCS, IEEE80211_TX_RC_GREEN_FIELD, IEEE80211_TX_RC_40_MHZ_WIDTH, IEEE80211_TX_RC_DUP_DATA, IEEE80211_TX_RC_SHORT_GI, IEEE80211_TX_RC_VHT_MCS, IEEE80211_TX_RC_80_MHZ_WIDTH, IEEE80211_TX_RC_160_MHZ_WIDTH }; CONSTANTS
IEEE80211_TX_RC_USE_RTS_CTS Use RTS/CTS exchange for this rate. IEEE80211_TX_RC_USE_CTS_PROTECT CTS-to-self protection is required. This is set if the current BSS requires ERP protection. IEEE80211_TX_RC_USE_SHORT_PREAMBLE Use short preamble. IEEE80211_TX_RC_MCS HT rate. IEEE80211_TX_RC_GREEN_FIELD Indicates whether this rate should be used in Greenfield mode. IEEE80211_TX_RC_40_MHZ_WIDTH Indicates if the Channel Width should be 40 MHz. IEEE80211_TX_RC_DUP_DATA The frame should be transmitted on both of the adjacent 20 MHz channels, if the current channel type is NL80211_CHAN_HT40MINUS or NL80211_CHAN_HT40PLUS. IEEE80211_TX_RC_SHORT_GI Short Guard interval should be used for this rate. IEEE80211_TX_RC_VHT_MCS VHT MCS rate, in this case the idx field is split into a higher 4 bits (Nss) and lower 4 bits (MCS number) IEEE80211_TX_RC_80_MHZ_WIDTH Indicates 80 MHz transmission IEEE80211_TX_RC_160_MHZ_WIDTH Indicates 160 MHz transmission (80+80 isn't supported yet) DESCRIPTION
These flags are set by the Rate control algorithm for each rate during tx, in the flags member of struct ieee80211_tx_rate. AUTHOR
Johannes Berg <johannes@sipsolutions.net> Author. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 ENUM MAC80211_RATE_C(9)

15 More Discussions You Might Find Interesting

1. Fedora

Is UNIX an open source OS ?

Hi everyone, I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX. Ok onto business, my questions are-: Was/Is UNIX ever an open source operating system ? If UNIX was... (21 Replies)
Discussion started by: sreyan32
21 Replies

2. UNIX for Beginners Questions & Answers

Weird 'find' results

Hello and thanks in advance for any help anyone can offer me I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
Discussion started by: bodisha
14 Replies

3. UNIX for Beginners Questions & Answers

Set hard block limit for user using quota

hi all, i have installed quota on my centos 7 machine and its what im after (setting size limit on users, so they cant fill the hard drive) i want to now make this part of my create user script for my sftp server so i want to do a echo and a read command so i capture the limit they enter... (0 Replies)
Discussion started by: robertkwild
0 Replies

4. UNIX for Beginners Questions & Answers

Best performance UNIX just for HOST Virtualization?

Hi everybody, Which Unix base OS have best performance for HOST virtualization? I tested SmartOS but it needs another OS to connect remotely! Thanks in advance. (11 Replies)
Discussion started by: mbzadegan
11 Replies

5. UNIX for Beginners Questions & Answers

How to increment version inside a file?

Hi All, I need to write a shell script which opens a file and increments the version(text) within the file every time the script runs. For example: $ cat docker_file.yml version: '3.1' services: ui: image: repo-srv.dev.io:5000/facebook/ui:0.0.2-QA1 $ So, I would like... (6 Replies)
Discussion started by: akshayupadhayay
6 Replies

6. Programming

DB2 convert digits to binary format

Dear Team We use DB2 v10.5 and using DBArtisan tool Can someone please guide how to convert digits to binary numbers using db2 feature. Ex> for number 9 , binary should be 1001 ( 8+1) Any help appreciated. Thanks (2 Replies)
Discussion started by: Perlbaby
2 Replies

7. UNIX for Advanced & Expert Users

Tar Command

hi folks, how to using tar with exclude directory and compress it using tar.Z i only know how to exclude dir only with this command below: tar -cvf /varios/restore/test.tar -X excludefile.txt /jfma/test1/ how to compress it using 1 command? Thanx Please use CODE tags as... (6 Replies)
Discussion started by: only
6 Replies

8. UNIX for Advanced & Expert Users

CentOS7 restoring file capabilities

Quite an obscure question I think. We have a rebuild process for remote sites that allows us to PXE rebuild a till (actually a PC with a touch screen and various fancy bits) running CentOS. The current CentOS5 tills work just fine with a tar image restore and some personalisation. Sadly,... (4 Replies)
Discussion started by: rbatte1
4 Replies

9. Docker

Docker learning Phase-I

Hello All, I had recently learnt a bit of Docker(which provides containerization process). Here are some of my learning points from it. Let us start first with very basic question: What is Docker: Docker is a platform for sysadmins and developers to DEPLOY, DEVELOP and RUN applications ... (7 Replies)
Discussion started by: RavinderSingh13
7 Replies

10. UNIX for Advanced & Expert Users

Shopt -s histappend

What is the point of this? Whenever I close my shell it appends to the history file without adding this. I have never seen it overwrite my history file. # When the shell exits, append to the history file instead of overwriting it shopt -s histappend (3 Replies)
Discussion started by: cokedude
3 Replies

11. UNIX for Beginners Questions & Answers

Unsure why access time on a directory change isn't changing

Hello... And thanks in advance for any help anyone can offer me I was trying to work out the differences between displaying modify, access, and change times with the 'ls' command. Everything seems in order when I look at files, but the access time on a directory doesn't seem to change when I... (4 Replies)
Discussion started by: bodisha
4 Replies

12. UNIX for Beginners Questions & Answers

CentOS 6 ran out of space, need to reclaim it

Hello everyone, I am having an issue here with CentOS release 6.6 (Final) that shows all of the space used up, but I can't tell where the space went. Seemingly I am using up 100%, according to df -h Filesystem Size Used Avail Use% Mounted on... (27 Replies)
Discussion started by: DannyBoyCentOS
27 Replies

13. Shell Programming and Scripting

Controlling user input

I'm trying to use a bash script for a psych experiment that involves listening to sound files and responding. If I have something like the code below, how can I make sure that a key press is assigned to RESPONSE only after the second echo statement? for i in 1 2 3; do echo "Ready?" sleep 2 ... (10 Replies)
Discussion started by: darwin_886
10 Replies

14. Shell Programming and Scripting

[TIP] Processing YAML files with yq

After the success of the jq - tool for parsing and manipulating JSON-Data someone wrote a tool called yq, which aims to be the same for YAML, what jq is for JSON. Seems to work fine. I'll definitely give it a chance in future. Example YAML-File: --- !ruby/object:Puppet::Node::Facts ... (1 Reply)
Discussion started by: stomp
1 Replies

15. What is on Your Mind?

Please Welcome Dave Munro to the Moderator Team!

Dear All, I am very pleased to announce that Dave Munro (gull04) is joining the Moderation Team, after being a very valuable member of UNIX.com for 15+ years. Dave is an IT Consultant with 30 years of experience this year, has worked in many of the industry vertical market segments and has... (6 Replies)
Discussion started by: Neo
6 Replies

Featured Tech Videos