Files and Directories

The Unix Shell

Files and Directories

Copyright © Software Carpentry 2010

This work is licensed under the Creative Commons Attribution License

See http://software-carpentry.org/license.html for more information.

Run

Programs

Store

Data

Files and Directories Introduction

Communicate

with each other

Interact

with us

Run

Programs

Store

Datashell

Files and Directories Introduction

Communicate

with each other

Interact

with us

Store

Datashell

Files and Directories Introduction

Store

Datashell

Files and Directories Introduction

file system

Store

Datashell

Files and Directories Introduction

file system

files

Store

Datashell

Files and Directories Introduction

file system

files directories

Store

Datashell

Use the shell

Files and Directories Introduction

file system

files directories

Use the shell

to view and change

the file system

Store

DatashellUse the shell

to run commands

Files and Directories Introduction

file system

files directories

to run commands

to view what's in

the file system

login:login:login:login:

Files and Directories Introduction

login:login:login:login: computer prompt in bold

Files and Directories Introduction

login:login:login:login: computer prompt in bold

explanatory text in blueexplanatory text in blue

Files and Directories Introduction

login:login:login:login: vlad user input in green

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ******** password

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ shell prompt

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ shell prompt

like Python's >>> and …like Python's >>> and …

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami check user ID

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami check user ID

shell finds the whoami programshell finds the whoami program

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami check user ID

shell finds the whoami programshell finds the whoami program

runs it

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

check user ID

shell finds the whoami programvlad shell finds the whoami program

runs it

prints its output

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

check user ID

shell finds the whoami programvlad

$$$$

shell finds the whoami program

runs it

prints its output

displays a new prompt

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd what is the working directory

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd what is the working directory

the directory used when no other

directory is explicitly specified

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

root

vlad

$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

imhotep larry vlad

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

imhotep larry vlad

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

imhotep larry vlad

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vlad

/

root

vlad

$$$$ pwd

/users/vlad

$$$$

bin data users tmp

imhotep larry vlad

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd

/users/vlad

$$$$ ls stands for "listing"

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd

/users/vlad

$$$$ ls stands for "listing"

sadly more memorable than

most command names

Files and Directories Introduction

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladvlad

$$$$ pwd

/users/vlad

$$$$ ls

bin data mail music

notes.txt papers pizza.cfg solar

solar.pdf swc

Files and Directories Introduction

solar.pdf swc

$$$$

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladan argument or flag modifying

vlad

$$$$ pwd

/users/vlad

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

an argument or flag modifying

the command's behavior

Files and Directories Introduction

solar.pdf swc/

$$$$

login:login:login:login: vlad

password:password:password:password: ********

$$$$ whoami

vladadds a trailing '/' to

vlad

$$$$ pwd

/users/vlad

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

adds a trailing '/' to

directory names

Files and Directories Introduction

solar.pdf swc/

$$$$

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/solar.pdf swc/

vlad

bin musicmail papersdata notes.txt

Files and Directories Introduction

solarpizza.cfg solar.pdf swc

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/solar.pdf swc/

By convention, use filename extension to indicate file type

Files and Directories Introduction

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/solar.pdf swc/

By convention, use filename extension to indicate file type

.txt for text, .pdf for PDF, .cfg for configuration file, etc.

Files and Directories Introduction

$$$$ ls -F

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/solar.pdf swc/

By convention, use filename extension to indicate file type

.txt for text, .pdf for PDF, .cfg for configuration file, etc.

But this is only a convention, not a guarantee

Files and Directories Introduction

$$$$ ls –F data

Files and Directories Introduction

$$$$ ls –F data

amino_acids.txt elements/ morse.txt

pdb/ planets.txt sunspot.txt

$$$$$$$$

Files and Directories Introduction

$$$$ ls –F data

amino_acids.txt elements/ morse.txt

pdb/ planets.txt sunspot.txt

$$$$

vlad

data

a relative path

$$$$

Files and Directories Introduction

$$$$ ls –F data

amino_acids.txt elements/ morse.txt

pdb/ planets.txt sunspot.txt

$$$$

vlad

data

a relative path

relative to

current working directory

$$$$

Files and Directories Introduction

$$$$ ls –F /data

access.log backup/ hardware.cfg

network.cfg

$$$$$$$$

Files and Directories Introduction

$$$$ ls –F /data

access.log backup/ hardware.cfg

network.cfg

$$$$

an absolute path

$$$$

Files and Directories Introduction

$$$$ ls –F /data

access.log backup/ hardware.cfg

network.cfg

$$$$

an absolute path

leading '/' means "from root"

$$$$

Files and Directories Introduction

$$$$ ls –F /data

access.log backup/ hardware.cfg

network.cfg

$$$$

bin data users tmp

/

an absolute path

leading '/' means "from root"

so it always refers to

this directory

$$$$

Files and Directories Introduction

imhotep larry vlad

$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$

Files and Directories Introduction

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

Files and Directories Introduction

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data change directory

Files and Directories Introduction

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

change directory

actually doesn't change the directory

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

Files and Directories Introduction

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

change directory

actually doesn't change the directory

changes the shell's idea of

which directory we are in

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

Files and Directories Introduction

which directory we are in

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

$$$$ pwd

/users/vlad/data

$$$$

Files and Directories Introduction

$$$$

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

$$$$ pwd

/users/vlad/data

$$$$ ls

Files and Directories Introduction

$$$$ ls

amino_acids.txt elements/ morse.txt

pdb/ planets.txt sunspot.txt

$$$$

$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

because we're now "in"

this directory

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ cd data

$$$$ pwd

/users/vlad/data

$$$$ ls

Files and Directories Introduction

$$$$ ls

amino_acids.txt elements/ morse.txt

pdb/ planets.txt sunspot.txt

$$$$

$$$$ pwd

/users/vlad/data

$$$$

Files and Directories Introduction

$$$$ pwd

/users/vlad/data

$$$$ cd ..

Files and Directories Introduction

$$$$ pwd

/users/vlad/data

$$$$ cd .. the directory above the current one

Files and Directories Introduction

$$$$ pwd

/users/vlad/data

$$$$ cd .. the directory above the current one

its parent directoryits parent directory

Files and Directories Introduction

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$

Files and Directories Introduction

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$

Files and Directories Introduction

$$$$

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ ls -F -a

Files and Directories Introduction

$$$$ ls -F -a

./ ../ bin/ data/

mail/ music/ notes.txt papers/

pizza.cfg solar/ solar.pdf swc/

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ ls -F -a

"show all"

Files and Directories Introduction

$$$$ ls -F -a

./ ../ bin/ data/

mail/ music/ notes.txt papers/

pizza.cfg solar/ solar.pdf swc/

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ ls -F -a

parent directory

Files and Directories Introduction

$$$$ ls -F -a

./ ../ bin/ data/

mail/ music/ notes.txt papers/

pizza.cfg solar/ solar.pdf swc/

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ ls -F -a

parent directory

Files and Directories Introduction

$$$$ ls -F -a

./ ../ bin/ data/

mail/ music/ notes.txt papers/

pizza.cfg solar/ solar.pdf swc/

/users

$$$$ pwd

/users/vlad/data

$$$$ cd ..

$$$$ pwd$$$$ pwd

/users/vlad

$$$$ ls

bin/ data/ mail/ music/

notes.txt papers/ pizza.cfg solar/

solar.pdf swc/

$$$$ ls -F -a

this directory

itself

Files and Directories Introduction

$$$$ ls -F -a

./ ../ bin/ data/

mail/ music/ notes.txt papers/

pizza.cfg solar/ solar.pdf swc/

itself

Things are different on Windows

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Drive letter

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Drive letter

Each drive is a separate file system

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Backslash \ as separator

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Backslash \ as separator

Unix uses \ to escape special characters

in names like my\ files.txt

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Case insensitive

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Case insensitive

c:\users\vlad C:\USERS\VLAD C:\uSeRs\VlAd

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Cygwin: /cygdrive/c/Users/vlad

Map drive letters to "directories"

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Cygwin: /cygdrive/c/Users/vlad

Map drive letters to "directories"

And use / instead of \

Files and Directories Introduction

Things are different on Windows

C:\Users\vlad

Cygwin: /cygdrive/c/Users/vlad

Map drive letters to "directories"

And use / instead of \

Files and Directories Introduction

But still case insensitive

Things are different on Windows

C:\Users\vlad

Cygwin: /cygdrive/c/Users/vlad

Map drive letters to "directories"

And use / instead of \

Files and Directories Introduction

But still case insensitive

Can't put backup.txt and Backup.txt in a directory

pwd print working directory

cd change working directory

ls listingls listing

. current directory

.. parent directory

Files and Directories Introduction

August 2010

created by

Greg Wilson

August 2010

Copyright © Software Carpentry 2010

This work is licensed under the Creative Commons Attribution License

See http://software-carpentry.org/license.html for more information.