isecur1ty training center Presented by Eng Mohammad Khreesha Table of contents Introduction Getting help in Linux m an pages a propos man k w hatis whereis man sections h option ID: 212613
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Slide1
Linux Essentials
isecur1ty training center
Presented by : Eng. Mohammad Khreesha Slide2
Table of contents
Introduction
Getting help in Linux
m
an pages
a
propos (man –k)
w
hatis
whereis
man sections
-h option
infoSlide3
Introduction
The command line is the tool that all GUI applications use to do their
work.
In
other words: graphical tools are merely front-ends to command line tools. Slide4
Linux command structure
The basic Linux command works like this
:
command
[OPTIONS]
[ARGUMENTS ]
command: This is the base of the command
.
OPTIONS: Options are those pieces of the command that alter the behavior of the command
.
ARGUMENTS: Arguments are typically file names or other data that is needed by the command
.
Example:
mkdir
-m 654 TEST (create the directory TEST with the mode 654
) Slide5
Getting help in Linux
This module will guide you to the correct way for getting help in Linux without searching
on internet ….
We will discuss multiple ways to get help in
linux
…Slide6
man pages
The
man pages are a user manual that is by default built into most Linux distributions (i.e., versions) and most other Unix-like operating systems during installation. They provide extensive documentation about commands and other aspects of the system, including configuration files, system calls, library routines and the kernel
…..
Examples:
man
whois
man
syslog.conf
man
syslogdSlide7
apropos (man –k)
The apropos command displays a list of all topics in the man pages that are related to the subject of a query
.
Examples:
man -k
syslog
or apropos
syslogSlide8
whatis (man –f)
The
whatis
command provides very brief descriptions of command line programs and other topics related to Linux and other Unix-like operating systems
.
Examples:
whatis
cat or man –f catSlide9
whereis
whereis
used to
locate the binary, source, and manual page files for a
command…
Examples:
whereis
tar
Slide10
man sections
The manual is generally split into eight numbered sections, organized as
follows :
Executable
programs or shell commands
System
calls (functions provided by the kernel)
Library
calls (functions within program libraries)
Special
files (usually found in /dev)
File
formats and conventions
eg
/etc/
passwd
Games
Miscellaneous
(including macro packages and conventions), e.g. man(7)
System
administration commandsSlide11
continue…
Examples :
man
passwd
:
opens the first manual found
man 5
passwd
:
opens a page from section 5Slide12
man man
If you want to know more and more about man pages you can get help about man (manual) pages like this :
man
man
Note : man pages don’t have answers for everything like : man hello
Slide13
-h option or --help
Sometimes you may know the functionality of a command very well, but cannot recollect all the available options for a specific command. Use -h option of the command to review all available options of the command
.
Examples :
cat –help
netstat
-hSlide14
info
Display a file’s help information in an alternate format
.
Some programs don’t have man pages – or have very incomplete man pages – and store their documentation as info documents
.
Examples:
i
nfo catSlide15
The end