UNIX

情報ネットワーク特論資料

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UNIX commands for manipulating files and directories

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Command Description

mkdir / rmdir create and remove directories

cd change current directory

pwd show current directory

ls list files and directories

cp copy

mv move or change name

rm remove

cat show text file

less show text file page by page

Operations for editing commands

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Operation Function

→ Move cursor right

← Move cursor left

C-a Go to the left-end

C-e Go to the right-end

C-u Cut entire line

C-k Cut from here to the left-end

C-y Paste

↑ Go to the older commands in the history

↓ Go to the newer commands in the history

TAB key Complete file name or command name

Hierarchical structure of file system on UNIX

File system on UNIX is hierarchically constructed with"directories" and "files"

directory= "folder" of Windows and Mac

Store files and other directories

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unix memo.txtmemo.txt

test1.txttest1.txt

sample.csample.c

fortran

programming

directory

file

prog1.f90prog1.f90

prog2.f90prog2.f90

prog3.f90prog3.f90

Special directories

root directory: "root" of the entire hierarchy

home directory: Your "home" place

You can create or delete files and directoriesunder this directory

current directory: Directory you are working at

You can change "current directory" by cd command of UNIX

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/

usrtmphomeetc

00nen

1234567890

unix

test1.txttest1.txt

01nen students

1000000000

rootdirectory

homedirectory

currentdirectory

"Path" of files and directories

Path= location of a file or a directory Path to reach to the file or directory

"xx/" means "under xx directory"

xx/yy/zz = zz under yy under xx

Used to specify files and directories for UNIX commands

Relative path: path from "current directory"

Absolute path path from "root directory"

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/home/students/1234567890/unix/test1.txt

unix/test1.txt

relative path from /home/students/1234567890

absolute path

Example:path to this file

test1.txt

relative path from/home/students/1234567890/unix

mkdir / rmdir

mkdir: MaKe DIRectory create one or more directories

rmdir: ReMove DIRectory only "empty" directory can be

removed

to remove non-empty directory, use "rm" command

Examples) make a directory test in work

directory in the current directory

make multiple directories in the current directory

remove directory work in test directory in the current directory

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$ mkdir work/test

$ mkdir test1 test2 test3

$ rmdir test/work

cd

cd: Change current Directory Why do we change the current

directory?=> To shorten the UNIX commands

For example: make three directories in "work" directory

from /home/students/1234567890

after moving to unix directory

Examples) Go back to your home directory

Go to directory test in the current directory

Go to directory work in the testdirectory in the current directory

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$ mkdir unix/dir0 unix/dir1 unix/dir2

$ cd unix$ mkdir dir0 dir1 dir2

$ cd test

$ cd test/work

$ cd

pwd

pwd: Print Working Directory "working directory"

= current directory

Execute this command frequently to check where you are now.

Since does not make any change on filesor directories

Avoid miss operation

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ls

ls: LiSt files and directories See names of files and directories in

current directory, or other directories UNIX does not show files even in the current

directory, automatically. => You need to do it by yourself.

Options: -l

Show detailed information of each file

-R

Show hierarchy of files and directories

-a

Show files whose name starts with "."

Usually those files are hidden

Examples) list files and directories in the current

directory

list files in the directories test1 and test2 (if they are directories)

list files test1 and test2(if they are files)

list detailed information of "test1"

list hierarchy of files in the current directory with information

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$ ls

$ ls test1 test2

$ ls test1 test2

$ ls -l test1

$ ls -lR$ ls -l test1-rw-r--r-- 1 z6nt03in students 193 Apr 22 22:35 test1

owner last update timesize

cp

cp: CoPy Copy files and/or directories

Copy 1 filecp original_file new_file

Copy 1 directorycp -R original_directory new_directory

Copy multiple files and/or directories to a directorycp file1 file2 file3 existing_directorycp -R file1 file2 dir1 dir2 existing_directory

Options:

-R

Copy directory with all files and directories in it.

-i

Confirm before overwriting existing files

Examples) Make a copy of the file "test1" as file

"test2"

Copy the file "test1" to the existing directory "test2"

Make a copy of the directory "test1" as "test2"

Copy the directory "test1" to the existing directory "test2"

Copy multiple files and directoriesto the existing directory "test4"

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$ cp test1 test2

$ cp -R test1 test2

$ cp test1 test2

$ cp -R test1 test2

$ cp -R test1 test2 test3 test4

test1test1

test1test1 test2

test2test2

test1test1

mv

mv: MoVe Move files (and/or directories)

or Change name of a file (or directory)

Move files and/or directories to directorymv file1 file2 dir1 dir2 existing_directry

Change name of a file (or directory)mv old_name new_name

Options:

-i

Confirm before overwriting existing files

Note:mv does not require "-R" option to move

directories

Examples) Change name of the file (or directory)

"test1" to "test2"

Move the file (or directory) "test1" to the existing directory "test2"

Move multiple files and directories to the existing directory "test4"

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$ mv test1 test2

$ mv test1 test2

$ mv test1 test2 test3 test4

test1test1

test1test1 test2

test2test2

test1test1

rm

rm: ReMove Remove files.

Note: UNIX does not have "Trash Box"= Removed files cannot be resumed.

Options:

-R

Remove entire directory

-i

Confirm before removing each file or directory

Examples) Remove files "test1" and "test2"

Remove directories "test1" and "test2"

Remove a directory "test" with confirmation

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$ rm test1 test2

$ rm -R test1 test2

$ rm -iR test

cat / less

cat: Show text file(s) at once

less: Show a text file page-by-page

use following keys in this command:

j or down cursor : down 1 line

k or up cursor : up 1 line

space : down 1 page

b : up 1 page

g : go to the top

G : go to the bottom

/ : search forward for a keyword

? : search backward for a keyword

q : quit

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Special symbols in path

/ (in the beginning of a path) root directory

.. 1-level upper directory

Ex) (from /home/students/1234567890)

. current directory

Ex)

~ home directory

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Example:(from /home/students/1234567890 )

/tmp

..

.

unix

unix/test1.txt

../1000000000~

absolute path

absolute path

relative path

relative path

relative path

relative path

relative path

/

absolute path

$ ls -l ../../00nen

$ cp unix/test1.txt .

Change Language

Login to ah.s.kyushu-u.ac.jp

Type the following commandand press Enter.

This will change your default language.

It take effects from next login.

Exit, and login again.

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$ echo export LANG=C >> ~/.bashrc

Create or modify programs:emacs

• Start text editer Emacs

• Usage:emacs filename

– If that file does not exist, create a new file– If that file exists, open it．

• Example: Create or start editing the file test.f90

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--uu:--F1 test.f90 (F90)--L1--All

$ emacs test.f90

View of Emacs

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--uu:--F1 test.f90 (F90)--L1--All

Text window: edit texts

Mode line:Displays the file name, current line number, etc.

Mini buffer:Displays commands or messagesFile name

Line numberwhere the cursor is.

Operations in EmacsOperation Function

C-f or → Move forward

C-b or ← Move backward

C-n or ↓ Move to the next line

C-p or ↑ Move to the previous line

C-d Delete the character at the cursor

delete Delete the character before the cursor

C-g Stop command

C-x C-s Save file

C-x C-c Exit Emacs

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C- means "Press the key with pressing Ctrl key"Ex. C-x Press x key with pressing Ctrl key

When the Emacs behaves unexpectedly

Press C-g for some times If Emacs returned to normal status, continue editing

If it didn't return, exit Emacs with C-x C-c Press y for "Save file .... ?"

Then restart Emacs by

emacs the_file_name_you_were_editing

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For more understanding

Read "UNIX Operating System" by Yukun Liu, et al Available from

http://www.springerlink.com

Specially, sections 3.1 and 3.8

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