Linux Basics

1
Chapter

• Linux Basics

2
Acknowledgements

• This presentation was prepared by
• Banyat Settapanich
• Bahran Madaen
• This presentation will be updated later

3
Introduction

• Command Line
• The standard utilities for manipulating files
• Features providing by shell
• File system
• Installation

4
Command line

• File handling utilities
• mkdir (MaKe DIRectory)
• Example
• mkdir foo - creates a directory foo in the
  current directory
• mkdir p images/misc docs - creates a directory
  misc in directory images

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Command line

• rm (ReMove)
• -r, or R Delete recursively
• -I Request confirmation before each deletion
• -f The opposite of I
• Example
• rm i images/.jpg file1- Deletes all files which
  name ends with .jpg in the current directory
• rm Rf images/misc/file - Deletes without
  requesting confirmation the whole directory misc/
  in directory images/ together with files in the
  currrent directory

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Command line

• mv (Move)
• -f Force file moving
• -i The opposite
• -v Verbose
• Example
• Mv I/tmp/pics/.gif - Move al files in directory
  /tmp/pics/ which name ends with .gif to the
  current directory
• mv foo bar - Rename file foo as bar

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Command line

• Cp (CoPy)
• -R Recursive copy
• -i Request confirmation before overwriting any
  files
• -f The opposite of i
• -v Verbose
• Example
• cp i /tmp/images/images/ - Copies all file from
  directory /tmp/images to directory images/ of the
  current directory
• cp foo bar - Make a copy of file foo under the
  name bar in the current directory

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Command line

• Handling File Attributes
• chown, chgrp (change the owner and group of one
  or more files
• -R Recursive to change the owner of all files
  and subdirectories in a given directory
• -v Verbose mode, describes all actions performed
  by chown
• -c Like v, but only reports which files have
  been changed

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Command line

• Example
• chmod R o-w/shared/docs Recursively removes
  write permission for other on all files and
  subdirectories of /shared/docs
• chmod R og-w,o-x private Recursively removes
  write permission for the group and others for
  whole directory private/, and removes the
  execution permission for others.

10
Command line

• Shell globbing patterns and regular expressions
• ? matches one and only one character, whatever
  that character
• match any character found into the brackets
• ! match any character not found in the
  brackets
• c1,c2 matches c1 and c2

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Command line

• Example
• image/cars,space0-9/.jpg All filenames
  ending with .jpg in directory image/cars,
  image/space0, , image/space9, if such
  directories exist
• !a-z All files which names do not end with
  a lowercase letter in the current directory

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Command line

• Redirections
• Example
• Is image/.gif 1gtfile_list command (1) is
  redirected (gt) to the file named file_list
• Pipes
• Example
• Is images/.gif wc 1 The standard output of
  the Is command is redirected to the standard
  input of the wc command

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File System

• Files
• Character mode files
• Special system files which share the
  particularity that their contents are not
  buffered
• Block mode files
• Peripherals and as opposed to character files,
  their contents are buffered
• Symbolic links
• Common heavily used file in the system startup
  procedure
• Name pipes
• Similar to pipes used in shell but these one
  actually have names

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File System

• Links
• The directory itself (.)
• Parent directory (..)
• Anonymous
• Pipes
• The shell creates the pipe and operates before
  the pipe write to it
• Name pipes
• Opposite to the pipes used by shell

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File System

• Special files
• Character mode
• Files were buffered
• Block mode files
• Files were not buffered
• Symbolic links
• Files of a particular type whose sole contents is
  an arbitrary string

16
File System

• File attributes
• A (no Access time)
• a (append only)
• d (no dump)
• i (immutable)
• s (secure deletion)
• S (Synchronous mode)

17
Installation

• Requirements
• A computer with a working operating system
• General knowledge of the operating system you use
• Some space on your hard disk
• A compiler (usually for the C language) and an
  archiver (tar)

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Installation

• Compilation
• Principle
• Translate a source code into a binary file
• Logically done by a C compiler
• Repetitive operations are handled by a utility
  name make

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Installation

• Four steps of compilation
• cpp consists in replacing directive
  (preprocessors) by pure C instructions
• ccl consists in converting C into assembly
  language
• as consists in generating object (or binary)
  code from the assembly language
• ld links all the object files (.o) and the
  associated libraries

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Installation

• Structure of a distribution
• An install file, which describes the installation
  procedure
• A readme file, which contains general information
  related to the program
• A copying file, which contains the license or
  describes the distribution conditions of the
  software
• A contrib or credits file, which contains a list
  of people related to the software

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Installation

• A changes file, which contains recent
  improvements and bugfixes
• A makefile file, which allows compilation of the
  software
• A configure or Imakefile file, which allow one to
  generate a new Makefile
• A directory that contains the sources (src)
• A directory that contains the document (doc)

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Installation

• Decompression
• tar.gz archive
• Gzip is a standard format
• Developed by the GNU project
• Consider as one of the best general compression
  tools
• Gzip is often associated with a utility name
  tar.tar

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Installation

• The use of GNU Tar
• v make tar verbose
• f is a required option
• z allows you to treat a gziped
• Tar allow you to perform several actions on an
  archive

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Installation

• Configuration
• Use Autoconf if a file named configure exists in
  the parent directory of the distribution
• Use Imake if a file name Imakefile exists in the
  parent directory of the distribution
• Run a shell script according to the contents of
  the INSTALL file

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Installation

• Compilation
• make
• The developer saves time because it allows one to
  efficiently manage compilation of his interests
• Compile and install the software in few command
  lines
• Rules
• make operates in accordance with a system of
  dependencies
• Compiling a binary file requires to go through
  several stages

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Installation

• Go, go, go!
• make without argument just executes the
  compilation of the program
• make install compile and provides the
  installation of the required files at the right
  place on the file system
• make clean clears all the temporary files created
  by the compilation

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Installation

• Support
• Documentation
• Look on your disk in /usr/doc/HOWTO
• Type man ltcommandgt to get documentation on the
  command ltcommandgt
• Technical support
• Newsgroup (on Usenet) comp.os.linux
• Several IRC channel (linuxhelp) on IRCNET
• Ask the developer of the software

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Installation

• How to find free software
• FTP site sundite.unc.edu
• http//www.freshmeat.net/ is probably the most
  complete site
• http//linux-france.org/ contains a lot of links
  to software working with GNU/Linux
• http//www.gnu.org/software/ for an exhaustive
  list of all of GNU software

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Linux-Mandrake information source

• http//www.linux-mandrake.com/guides71/en/mdkrefgu
  ide/fs-and-mntpoints.htm
• http//metalab.unc.edu/mdw/FAQ/Linux-FAQ/x13.html
• http//www.linuxdoc.org/
• http//www.linux-mandrake.com/en/
• http//faqs.jmas.co.jp/FAQs/linux/faq/

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End of presentation