The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line...
Transcript of The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line...
![Page 1: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/1.jpg)
The Command Line
Matthew Bender
CMSC Command Line Workshop
September 10, 2015
Matthew Bender (2015) The Command Line September 10, 2015 1 / 25
![Page 2: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/2.jpg)
Introduction
Section 1
Introduction
Matthew Bender (2015) The Command Line September 10, 2015 2 / 25
![Page 3: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/3.jpg)
Introduction
This Class
email: [email protected]
website: www.cs.umd.edu/command line
Meets Fridays from 2-3 in CSIC 3118
No office hours, but I’m reachable through email
Matthew Bender (2015) The Command Line September 10, 2015 3 / 25
![Page 4: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/4.jpg)
Introduction
Introduction
Why use the command line instead of a GUI?
More powerful - you have tons of tools at your disposal.
More control - tools tend to have many options, you choose exactlywhat to do.
Scriptable - if there is a sequence of commands you find yourselfentering a lot, you can make it into a script to run easily andautomate your work.
Faster workflow - typing commands if faster than clicking if you knowwhat you’re doing.
Composable - small, single-purpose commands can be combined to dopowerful things.
Matthew Bender (2015) The Command Line September 10, 2015 4 / 25
![Page 5: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/5.jpg)
Introduction
Introduction
Why use the command line instead of a GUI?
More powerful - you have tons of tools at your disposal.
More control - tools tend to have many options, you choose exactlywhat to do.
Scriptable - if there is a sequence of commands you find yourselfentering a lot, you can make it into a script to run easily andautomate your work.
Faster workflow - typing commands if faster than clicking if you knowwhat you’re doing.
Composable - small, single-purpose commands can be combined to dopowerful things.
Matthew Bender (2015) The Command Line September 10, 2015 4 / 25
![Page 6: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/6.jpg)
Introduction
Introduction
Why use the command line instead of a GUI?
More powerful - you have tons of tools at your disposal.
More control - tools tend to have many options, you choose exactlywhat to do.
Scriptable - if there is a sequence of commands you find yourselfentering a lot, you can make it into a script to run easily andautomate your work.
Faster workflow - typing commands if faster than clicking if you knowwhat you’re doing.
Composable - small, single-purpose commands can be combined to dopowerful things.
Matthew Bender (2015) The Command Line September 10, 2015 4 / 25
![Page 7: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/7.jpg)
Introduction
Introduction
Why use the command line instead of a GUI?
More powerful - you have tons of tools at your disposal.
More control - tools tend to have many options, you choose exactlywhat to do.
Scriptable - if there is a sequence of commands you find yourselfentering a lot, you can make it into a script to run easily andautomate your work.
Faster workflow - typing commands if faster than clicking if you knowwhat you’re doing.
Composable - small, single-purpose commands can be combined to dopowerful things.
Matthew Bender (2015) The Command Line September 10, 2015 4 / 25
![Page 8: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/8.jpg)
Introduction
Introduction
Why use the command line instead of a GUI?
More powerful - you have tons of tools at your disposal.
More control - tools tend to have many options, you choose exactlywhat to do.
Scriptable - if there is a sequence of commands you find yourselfentering a lot, you can make it into a script to run easily andautomate your work.
Faster workflow - typing commands if faster than clicking if you knowwhat you’re doing.
Composable - small, single-purpose commands can be combined to dopowerful things.
Matthew Bender (2015) The Command Line September 10, 2015 4 / 25
![Page 9: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/9.jpg)
Introduction
Composable Commands
Suppose we have a file called server.log :
72.30.61.37 "GET /hw/hw1.html HTTP/1.0"128.8.128.160 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"64.4.8.94 "GET /projects/p1.html HTTP/1.0"72.30.61.37 "GET /projects/p1.html HTTP/1.0"128.8.128.160 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw2.html HTTP/1.0"
Matthew Bender (2015) The Command Line September 10, 2015 5 / 25
![Page 10: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/10.jpg)
Introduction
Composable Commands
We want to know all the pages that IP address 72.30.61.37 visited.
How would we do that?We can combine several Linux commands to do so.
Matthew Bender (2015) The Command Line September 10, 2015 6 / 25
![Page 11: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/11.jpg)
Introduction
Composable Commands
We want to know all the pages that IP address 72.30.61.37 visited.How would we do that?
We can combine several Linux commands to do so.
Matthew Bender (2015) The Command Line September 10, 2015 6 / 25
![Page 12: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/12.jpg)
Introduction
Composable Commands
We want to know all the pages that IP address 72.30.61.37 visited.How would we do that?We can combine several Linux commands to do so.
Matthew Bender (2015) The Command Line September 10, 2015 6 / 25
![Page 13: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/13.jpg)
Introduction
Composable Commands
First, we use the fgrep command to choose only lines with the IPaddress we care about:
$ fgrep "72.30.61.37" server.log
72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /projects/p1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw2.html HTTP/1.0"
Matthew Bender (2015) The Command Line September 10, 2015 7 / 25
![Page 14: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/14.jpg)
Introduction
Composable Commands
However, we still have duplicates. We can remove these by first sorting thelines to group identical ones:
$ fgrep "72.30.61.37" server.log | sort
72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw2.html HTTP/1.0"72.30.61.37 "GET /projects/p1.html HTTP/1.0"
Matthew Bender (2015) The Command Line September 10, 2015 8 / 25
![Page 15: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/15.jpg)
Introduction
Composable Commands
Now we just need to remove the duplicates, which is easy using the uniqcommand:
$ fgrep "72.30.61.37" server.log | sort | uniq
72.30.61.37 "GET /hw/hw1.html HTTP/1.0"72.30.61.37 "GET /hw/hw2.html HTTP/1.0"72.30.61.37 "GET /projects/p1.html HTTP/1.0"
Matthew Bender (2015) The Command Line September 10, 2015 9 / 25
![Page 16: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/16.jpg)
Getting Set Up
Section 2
Getting Set Up
Matthew Bender (2015) The Command Line September 10, 2015 10 / 25
![Page 17: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/17.jpg)
Getting Set Up
Getting to a CLI
There are several ways you can work on a terminal.Linux: just open up your terminal emulator.Mac: open the Terminal application. (Some programs may be slightlydifferent).Windows: download and install Cygwin. (Some programs and behaviormay be different).
Matthew Bender (2015) The Command Line September 10, 2015 11 / 25
![Page 18: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/18.jpg)
Getting Set Up
Getting to a Linux CLI
Use a VM: Download VirtualBox, get a Linux image and install.If you have a Grace/Linuxlab account, or access to a different Linuxserver, you can SSH into it.Linux and Mac: use the ssh commandWindows: download and install PuTTYMore detailed instructions are on the website.
Matthew Bender (2015) The Command Line September 10, 2015 12 / 25
![Page 19: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/19.jpg)
Getting Started
Section 3
Getting Started
Matthew Bender (2015) The Command Line September 10, 2015 13 / 25
![Page 20: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/20.jpg)
Getting Started
Shells
When you open a terminal/SSH into a server, a program called a shellruns.
There are many different shells, the most common of which is called bash.A shell waits for you to type in commands, and then takes an action orlaunches a program for you.Any output from the commands is printed back to you.Shells provide extra features to help you do exactly what you want.
Matthew Bender (2015) The Command Line September 10, 2015 14 / 25
![Page 21: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/21.jpg)
Getting Started
Shells
When you open a terminal/SSH into a server, a program called a shellruns.There are many different shells, the most common of which is called bash.
A shell waits for you to type in commands, and then takes an action orlaunches a program for you.Any output from the commands is printed back to you.Shells provide extra features to help you do exactly what you want.
Matthew Bender (2015) The Command Line September 10, 2015 14 / 25
![Page 22: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/22.jpg)
Getting Started
Shells
When you open a terminal/SSH into a server, a program called a shellruns.There are many different shells, the most common of which is called bash.A shell waits for you to type in commands, and then takes an action orlaunches a program for you.
Any output from the commands is printed back to you.Shells provide extra features to help you do exactly what you want.
Matthew Bender (2015) The Command Line September 10, 2015 14 / 25
![Page 23: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/23.jpg)
Getting Started
Shells
When you open a terminal/SSH into a server, a program called a shellruns.There are many different shells, the most common of which is called bash.A shell waits for you to type in commands, and then takes an action orlaunches a program for you.Any output from the commands is printed back to you.
Shells provide extra features to help you do exactly what you want.
Matthew Bender (2015) The Command Line September 10, 2015 14 / 25
![Page 24: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/24.jpg)
Getting Started
Shells
When you open a terminal/SSH into a server, a program called a shellruns.There are many different shells, the most common of which is called bash.A shell waits for you to type in commands, and then takes an action orlaunches a program for you.Any output from the commands is printed back to you.Shells provide extra features to help you do exactly what you want.
Matthew Bender (2015) The Command Line September 10, 2015 14 / 25
![Page 25: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/25.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 26: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/26.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 27: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/27.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 28: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/28.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 29: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/29.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 30: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/30.jpg)
Getting Started
Basic Commands
date - output the current date and time
cal - show a calander
Commands can take arguments and options:
the -3 option can be added telling cal to output the previous,current, and next month.
An argument can be passed like 1999 to tell cal to show all of 1999.
Options and arguments are passed in the same way - adding them tothe command - cal -3 or cal 1999
Matthew Bender (2015) The Command Line September 10, 2015 15 / 25
![Page 31: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/31.jpg)
Basic Filesystem Commands
Section 4
Basic Filesystem Commands
Matthew Bender (2015) The Command Line September 10, 2015 16 / 25
![Page 32: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/32.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 33: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/33.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 34: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/34.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 35: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/35.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 36: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/36.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 37: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/37.jpg)
Basic Filesystem Commands
Filesystem Structure
Computers need a way to organize their files
Most filesystems have a tree-like structure
Linux starts with the root directory, just called /
Each directory can have files and more directories inside it
You can specify a file or directory by its full path from the rootdirectory. /etc/passwd refers to a file called passwd in thedirectory etc/ which itself is in the root directory /
When working on the command line, you are in a directory. This iscalled your ”working directory”.
Matthew Bender (2015) The Command Line September 10, 2015 17 / 25
![Page 38: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/38.jpg)
Basic Filesystem Commands
Basic Filesystem Commands
pwd - print working directory
ls - list the files in the given directory, or the current directory ifnone is given.
cd - change directory - move to a different directory
Matthew Bender (2015) The Command Line September 10, 2015 18 / 25
![Page 39: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/39.jpg)
Basic Filesystem Commands
Basic Filesystem Commands
pwd - print working directory
ls - list the files in the given directory, or the current directory ifnone is given.
cd - change directory - move to a different directory
Matthew Bender (2015) The Command Line September 10, 2015 18 / 25
![Page 40: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/40.jpg)
Basic Filesystem Commands
Basic Filesystem Commands
pwd - print working directory
ls - list the files in the given directory, or the current directory ifnone is given.
cd - change directory - move to a different directory
Matthew Bender (2015) The Command Line September 10, 2015 18 / 25
![Page 41: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/41.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:
I / is the root directoryI . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 42: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/42.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:
I / is the root directoryI . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 43: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/43.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:
I / is the root directoryI . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 44: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/44.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:I / is the root directory
I . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 45: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/45.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:I / is the root directoryI . is the current directory
I .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 46: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/46.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:I / is the root directoryI . is the current directoryI .. is the current directory’s parent
I ˜ is your home directory - this is where your current directory starts aswhen you start a shell
I ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 47: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/47.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:I / is the root directoryI . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shell
I ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 48: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/48.jpg)
Basic Filesystem Commands
Filesystem Shortcuts
Referring to files and directories by their full name is inconvenient
You can also refer to them by their name relative to your currentdirectory. If you are in /home/bender/, then the files/home/bender/file.txt and file.txt will refer to the samefile.
There are also special directory names:I / is the root directoryI . is the current directoryI .. is the current directory’s parentI ˜ is your home directory - this is where your current directory starts as
when you start a shellI ˜bender is user bender’s home directory
As a side note, /, ., and .. are actual directory names. ˜ is acharacter recognized by your shell, which then replaces it with thehome directory of a user or you
Matthew Bender (2015) The Command Line September 10, 2015 19 / 25
![Page 49: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/49.jpg)
Basic Filesystem Commands
Man Pages
The man pages (short for manual) provide help on commands, topics,and even C functions
Use the man command to bring up a topic’s man page
man pages tend to be long, so they will be displayed with a pagerprogram - usually less - which allows you to scroll through thecontent. These can usually be exited by hitting q.
We will go more into detail with the man pages and pagers in thefuture
And if you can’t figure out how to use the man pages, run man man
Matthew Bender (2015) The Command Line September 10, 2015 20 / 25
![Page 50: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/50.jpg)
Basic Filesystem Commands
Man Pages
The man pages (short for manual) provide help on commands, topics,and even C functions
Use the man command to bring up a topic’s man page
man pages tend to be long, so they will be displayed with a pagerprogram - usually less - which allows you to scroll through thecontent. These can usually be exited by hitting q.
We will go more into detail with the man pages and pagers in thefuture
And if you can’t figure out how to use the man pages, run man man
Matthew Bender (2015) The Command Line September 10, 2015 20 / 25
![Page 51: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/51.jpg)
Basic Filesystem Commands
Man Pages
The man pages (short for manual) provide help on commands, topics,and even C functions
Use the man command to bring up a topic’s man page
man pages tend to be long, so they will be displayed with a pagerprogram - usually less - which allows you to scroll through thecontent. These can usually be exited by hitting q.
We will go more into detail with the man pages and pagers in thefuture
And if you can’t figure out how to use the man pages, run man man
Matthew Bender (2015) The Command Line September 10, 2015 20 / 25
![Page 52: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/52.jpg)
Basic Filesystem Commands
Man Pages
The man pages (short for manual) provide help on commands, topics,and even C functions
Use the man command to bring up a topic’s man page
man pages tend to be long, so they will be displayed with a pagerprogram - usually less - which allows you to scroll through thecontent. These can usually be exited by hitting q.
We will go more into detail with the man pages and pagers in thefuture
And if you can’t figure out how to use the man pages, run man man
Matthew Bender (2015) The Command Line September 10, 2015 20 / 25
![Page 53: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/53.jpg)
Basic Filesystem Commands
Man Pages
The man pages (short for manual) provide help on commands, topics,and even C functions
Use the man command to bring up a topic’s man page
man pages tend to be long, so they will be displayed with a pagerprogram - usually less - which allows you to scroll through thecontent. These can usually be exited by hitting q.
We will go more into detail with the man pages and pagers in thefuture
And if you can’t figure out how to use the man pages, run man man
Matthew Bender (2015) The Command Line September 10, 2015 20 / 25
![Page 54: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/54.jpg)
Basic Filesystem Commands
Creating Files
There are many ways to create and edit files via the command line. Fornow, we will briefly cover text editors.
There are many text editors, such as emacs and vim, but the easiest touse is probably nano.
Open a file with $ nano file.txt, edit it, and save it. There aremuch better text editors out there, but for now this is the simplest.
Matthew Bender (2015) The Command Line September 10, 2015 21 / 25
![Page 55: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/55.jpg)
Basic Filesystem Commands
More Basic Commands - cat
cat - catenate file - prints the contents of a file
$ cat file1.txt file2.txt file3.txt : outputs the contentsof each file
If no arguments are given, cat reads the user’s input and outputs that
The -n option to cat adds line numbers to the output
Matthew Bender (2015) The Command Line September 10, 2015 22 / 25
![Page 56: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/56.jpg)
Basic Filesystem Commands
More Basic Commands - cat
cat - catenate file - prints the contents of a file
$ cat file1.txt file2.txt file3.txt : outputs the contentsof each file
If no arguments are given, cat reads the user’s input and outputs that
The -n option to cat adds line numbers to the output
Matthew Bender (2015) The Command Line September 10, 2015 22 / 25
![Page 57: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/57.jpg)
Basic Filesystem Commands
More Basic Commands - cat
cat - catenate file - prints the contents of a file
$ cat file1.txt file2.txt file3.txt : outputs the contentsof each file
If no arguments are given, cat reads the user’s input and outputs that
The -n option to cat adds line numbers to the output
Matthew Bender (2015) The Command Line September 10, 2015 22 / 25
![Page 58: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/58.jpg)
Basic Filesystem Commands
More Basic Commands - cat
cat - catenate file - prints the contents of a file
$ cat file1.txt file2.txt file3.txt : outputs the contentsof each file
If no arguments are given, cat reads the user’s input and outputs that
The -n option to cat adds line numbers to the output
Matthew Bender (2015) The Command Line September 10, 2015 22 / 25
![Page 59: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/59.jpg)
Basic Filesystem Commands
More Basic Commands - cp
cp - copy file to make a duplicate
$ cp source.txt dest.txt : copies the file source.txt to thefile dest.txtif dest.txt already exists, then it will be overwritten, unless the -n (noclobber) flag is set, in which case no copy happens, or the -i (interactive)flag is given, in which case cp will ask what you what to do.
the -r will recursively copy a directory and all files and subdirectoriesrooted there: $ cp -r source-dir dest-dir
Matthew Bender (2015) The Command Line September 10, 2015 23 / 25
![Page 60: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/60.jpg)
Basic Filesystem Commands
More Basic Commands - cp
cp - copy file to make a duplicate
$ cp source.txt dest.txt : copies the file source.txt to thefile dest.txt
if dest.txt already exists, then it will be overwritten, unless the -n (noclobber) flag is set, in which case no copy happens, or the -i (interactive)flag is given, in which case cp will ask what you what to do.
the -r will recursively copy a directory and all files and subdirectoriesrooted there: $ cp -r source-dir dest-dir
Matthew Bender (2015) The Command Line September 10, 2015 23 / 25
![Page 61: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/61.jpg)
Basic Filesystem Commands
More Basic Commands - cp
cp - copy file to make a duplicate
$ cp source.txt dest.txt : copies the file source.txt to thefile dest.txtif dest.txt already exists, then it will be overwritten, unless the -n (noclobber) flag is set, in which case no copy happens, or the -i (interactive)flag is given, in which case cp will ask what you what to do.
the -r will recursively copy a directory and all files and subdirectoriesrooted there: $ cp -r source-dir dest-dir
Matthew Bender (2015) The Command Line September 10, 2015 23 / 25
![Page 62: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/62.jpg)
Basic Filesystem Commands
More Basic Commands - cp
cp - copy file to make a duplicate
$ cp source.txt dest.txt : copies the file source.txt to thefile dest.txtif dest.txt already exists, then it will be overwritten, unless the -n (noclobber) flag is set, in which case no copy happens, or the -i (interactive)flag is given, in which case cp will ask what you what to do.
the -r will recursively copy a directory and all files and subdirectoriesrooted there: $ cp -r source-dir dest-dir
Matthew Bender (2015) The Command Line September 10, 2015 23 / 25
![Page 63: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/63.jpg)
Basic Filesystem Commands
More Basic Commands - mv
mv - move or rename files
$ mv old.txt new.txt will rename old.txt to new.txt$ mv file.txt dest-dir will move file.txt into dest-dir
Like cp, mv supports the -n and -i options to deal with existingdestination filesUnlike cp, no -r flag is needed to deal with directories. Just do $ mvsource-dir dest-dir , but note different things will happen basedon if dest-dir already exists!
Matthew Bender (2015) The Command Line September 10, 2015 24 / 25
![Page 64: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/64.jpg)
Basic Filesystem Commands
More Basic Commands - mv
mv - move or rename files
$ mv old.txt new.txt will rename old.txt to new.txt
$ mv file.txt dest-dir will move file.txt into dest-dir
Like cp, mv supports the -n and -i options to deal with existingdestination filesUnlike cp, no -r flag is needed to deal with directories. Just do $ mvsource-dir dest-dir , but note different things will happen basedon if dest-dir already exists!
Matthew Bender (2015) The Command Line September 10, 2015 24 / 25
![Page 65: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/65.jpg)
Basic Filesystem Commands
More Basic Commands - mv
mv - move or rename files
$ mv old.txt new.txt will rename old.txt to new.txt$ mv file.txt dest-dir will move file.txt into dest-dir
Like cp, mv supports the -n and -i options to deal with existingdestination filesUnlike cp, no -r flag is needed to deal with directories. Just do $ mvsource-dir dest-dir , but note different things will happen basedon if dest-dir already exists!
Matthew Bender (2015) The Command Line September 10, 2015 24 / 25
![Page 66: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/66.jpg)
Basic Filesystem Commands
More Basic Commands - rm
rm - remove files
$ rm file1 file2 file3 : remove each file given as an argument.Be careful! Once you do this, they are gone forever.rm supports the -i flag to ask if you’re sure before you delete the file. Italso supports the -f flag to force removal of a file, overriding an earlier-i flag
rm also supports the -r flag to recursively delete a directory and all itscontents. BE VERY CAREFUL WITH THIS: rm -rf dir willcompletely remove dir and all of its contents without asking - this is verydangerous
Matthew Bender (2015) The Command Line September 10, 2015 25 / 25
![Page 67: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/67.jpg)
Basic Filesystem Commands
More Basic Commands - rm
rm - remove files
$ rm file1 file2 file3 : remove each file given as an argument.Be careful! Once you do this, they are gone forever.
rm supports the -i flag to ask if you’re sure before you delete the file. Italso supports the -f flag to force removal of a file, overriding an earlier-i flag
rm also supports the -r flag to recursively delete a directory and all itscontents. BE VERY CAREFUL WITH THIS: rm -rf dir willcompletely remove dir and all of its contents without asking - this is verydangerous
Matthew Bender (2015) The Command Line September 10, 2015 25 / 25
![Page 68: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/68.jpg)
Basic Filesystem Commands
More Basic Commands - rm
rm - remove files
$ rm file1 file2 file3 : remove each file given as an argument.Be careful! Once you do this, they are gone forever.rm supports the -i flag to ask if you’re sure before you delete the file. Italso supports the -f flag to force removal of a file, overriding an earlier-i flag
rm also supports the -r flag to recursively delete a directory and all itscontents. BE VERY CAREFUL WITH THIS: rm -rf dir willcompletely remove dir and all of its contents without asking - this is verydangerous
Matthew Bender (2015) The Command Line September 10, 2015 25 / 25
![Page 69: The Command Line - University Of Maryland · 2015-09-10 · Matthew Bender (2015) The Command Line September 10, 2015 15 / 25. Getting Started Basic Commands date - output the current](https://reader034.fdocuments.us/reader034/viewer/2022050122/5f52bb331286655617619dd0/html5/thumbnails/69.jpg)
Basic Filesystem Commands
More Basic Commands - rm
rm - remove files
$ rm file1 file2 file3 : remove each file given as an argument.Be careful! Once you do this, they are gone forever.rm supports the -i flag to ask if you’re sure before you delete the file. Italso supports the -f flag to force removal of a file, overriding an earlier-i flag
rm also supports the -r flag to recursively delete a directory and all itscontents. BE VERY CAREFUL WITH THIS: rm -rf dir willcompletely remove dir and all of its contents without asking - this is verydangerous
Matthew Bender (2015) The Command Line September 10, 2015 25 / 25