Common OSX/Unix Commands

Common OS X/Unix Commands

Navigation Commands

1. cd: change directory

cd – : go back to previous directory

cd .. : go up to the parent of the current directory

cd ../..: go up two levels, to the parent’s parent directory

cd /: go to the top of the boot volume

cd /Users

cd ~ : go to home directory

cd ~/Documents

2. pwd: print working directory, the current path

3. ls: just list the names of the files in the current directory

ls –l: (long) list the files with their characteristics

ls –lo : list the files with their flags

ls –a: list all files in the current directory

ls –F: list filenames with a special character at the end that tells you what kind of file

it is

ls *.jpg: list the names of all files with names ending in ‘.jpg’

ls a*: list the names of all files start with ‘a’

ls *arr*: list the names of all files with names containing ‘arr’

File & Folder Manipulation Commands

1. cp: copy a file or directory

cp foo bar: copy a file named foo in current directory, and name the copy bar

cp foo ~/Documents: copy foo to Documents directory

cp foo ~/Documents/bar: copy foo to Documents, and name the copy bar

cp *.jpg ~/Documents: copy all jpg images to Documents

cp –R Documents “Documents backup”: back Documents, and name it Documents backup

sudo cp –Rp /Users “/Users backup”: copy entire Users directory preserving as much

as possible of the files information

2. mv: move of rename a file or folder

mv foo bar: rename foo to bar

mv foo ~/Documents: move foo to Documents directory

mv foo ~/Documents/bar: move foo to Documents and rename it to bar

mv *.jpg ~/Documents: move all jpg images to Documents

rm: remove a file /folder

rm foo: delete foo

rm a*: delete all files name start with a

rm *.jpg: delete all jpg images

rm –R temp: delete temp folder and all its contents

3. mkdir: make directory

mkdir foo: create a new directory foo

4. rmdir: remove an empty directory

5. ditto: copy a directory, preserving many characteristics of the enclosed files

6. chmod: change protection mode on files and folders, deal with complex access right with files

7. chflags: change a file or folder’s flags: arch, opaque, nodump, sappnd, schg, uappnd, uchg

chflags uchg foo: lock file or folder named foo against changes

chflags uappnd foo: make the file ‘foo’ append-only

chflags –R nouchg ~/Documents: unlock Documents and everything in it

8. chown: change the owner or group of a file or folder, must be root

sudo chown eva /Users/Shared/meeting-notes.txt: switch to root and assign eva as

the owner of meeting-notes.txt

sudo chown –R eva:staff /Users/Shared/temp: assign eva as the owner and staff as

the group for folder temp

9. chgrp: change the group of file or folder

chgrp staff /Users/Shared/meeting-notes.txt: Assign staff as the group of the file

chgrp –R staff /Users/temp: assign staff as the group of temp

Working with Text files

1. more and less: display the contents of a text file

2. tail: display the last few lines of a text file, useful for examining logs

tail -100 /var/log/system.log | more: use more to display last 100 lines of system.log

tail –f /var/log/system.log: print the last screenful of entries from system.log then

follow changes to file

3. vi, emacs, nano: other text editors, see man accordingly

4. tr ‘r’ ‘n’ <macfile.txt> unixfile.txt: convert Mac-format file to Unix-format file

Miscellaneous

1. su: set user, allow you to become another user, use ‘exit’ to back to normal

2. sudo: set user and do. Execute a single command as another user

sudo –u geoger ls ~geoger/Documents: become geoger and view his Documents

3. ps: list the processes running on the system

ps –ax: list all running processes

ps –aux: list all running processes with additional information about resource usage

4. top: list top CPU consuming processes running

top –us5 display processes sorted by CPU usage, updating 5 s

5. kill: kill process

kill 220: terminate process #220

6. ifconfig: configure network interfaces

ifconfig –a: list all network ports and their settings

7. man: display online documentation

man ls: display commands ls usages

8. apropos: list the manual pages relating to a particular keyword.

Apropos file: list manual pages mention ‘file’ in their summary file

9. clear: clear current screen

10. open: open a file in GUI

open ~Documents/foo: open folder foo

open –a /Applications/TextEdit.app ~/Documents/foo: use TextEdit to open foo

11. find: scan a directory structure for files matching certain criteria

find / -name foo: search entire file structure for files named exactly ‘foo’

find . –name foo: search current directory for foo

find .-mtime -2: search current directory for files modified within 2 days

find . –name *att*: searc h for files names contained ‘att’ in current directory

12. zip/unzip: package and compress files/decompress

13. gzip/ungzip

14. exit

15. reboot

16. shutdown –h now

Resize VirtualBox Hard Disk Size on OSX

  1. Shut Down VM, Stop VirtualBox
  2. Backup .vdi in Terminal type: VboxManage clonehd <path to original drive> <path for copy>
  3. Resize type in Terminal: VBoxManage modifyhd  <path> —resize 40960
  4. Restart VirtualBox, Start VM
  5. Extend System Disk in Windows OS in Computer Management tool

Lesson: Next time choose Dynamic Resizing Hard Disk when set up VirtualBox.

Basic vi Commands

Basic vi Commands

The UNIX vi editor is a full screen editor and has two modes of operation:

Command mode commands which cause action to be taken on the file, and

Insert mode in which entered text is inserted into the file.

In the command mode, every character typed is a command that does something to the text file

being edited; a character typed in the command mode may even cause the vi editor to enter the

insert mode.

In the insert mode, every character typed is added to the text in the file; pressing the <Esc> (Escape)

key turns off the Insert mode.

To Get Into and Out Of vi

To Start vi

To use vi on a file, type in vi filename. If the file named filename exists, then the first page (or

screen) of the file will be displayed; if the file does not exist, then an empty file and screen are

created into which you may enter text.

1. vi filename edit filename starting at line 1

2. vi -r filename recover filename that was being edited when system crashed

To Exit vi

Usually the new or modified file is saved when you leave vi. However, it is also possible to quit vi

without saving the file.

Note: The cursor moves to bottom of screen whenever a colon (:) is typed. This type of command is

completed by hitting the <Return> (or <Enter>) key.

1. :x<Return> quit vi, writing out modified file to file named in original invocation

2. :wq<Return> quit vi, writing out modified file to file named in original invocation

3. :q<Return>quit (or exit) vi

4. :q!<Return>quit vi even though latest changes have not been saved for this vi call

Moving the Cursor

Unlike many of the PC and MacIntosh editors, the mouse does not move the cursor within the vi

editor screen (or window).

You must use the the key commands listed below. On some UNIX platforms, the arrow keys may be

used as well; however, since vi was designed with the Qwerty keyboard (containing no arrow keys)

in mind, the arrow keys sometimes produce strange effects in vi and should be avoided.

If you go back and forth between a PC environment and a UNIX environment, you may find that this

dissimilarity in methods for cursor movement is the most frustrating difference between the two.

In the table below, the symbol ^ before a letter means that the <Ctrl> key should be held down

while the letter key is pressed.

1. j or <Return> [or down-arrow] move cursor down one line

2. k [or up-arrow] move cursor up one line

3. h or <Backspace> [or left-arrow] move cursor left one character

4. l or <Space> [or right-arrow] move cursor right one character

5. 0 (zero) move cursor to start of current line (the one with the cursor)

6. $ move cursor to end of current line

7. w move cursor to beginning of next word

8. b move cursor back to beginning of preceding word

9. :0<Return> or 1G move cursor to first line in file

10. :n<Return> or nG move cursor to line n

11. :$<Return> or G move cursor to last line in file

Screen Manipulation

The following commands allow the vi editor screen (or window) to move up or down several lines

and to be refreshed.

1. ^f move forward one screen

2. ^b move backward one screen

3. ^d move down (forward) one half screen

4. ^u move up (back) one half screen

5. ^l redraws the screen

6. ^r redraws the screen, removing deleted lines

Adding, Changing, and Deleting Text

Unlike PC editors, you cannot replace or delete text by highlighting it with the mouse. Instead use

the commands in the following tables.

Perhaps the most important command is the one that allows you to back up and undo your last

action. Unfortunately, this command acts like a toggle, undoing and redoing your most recent

action. You cannot go back more than one step.

1. u UNDO WHATEVER YOU JUST DID; a simple toggle

The main purpose of an editor is to create, add, or modify text for a file.

Inserting or Adding Text

The following commands allow you to insert and add text. Each of these commands puts the vi

editor into insert mode; thus, the <Esc> key must be pressed to terminate the entry of text and to

put the vi editor back into command mode.

1. i insert text before cursor, until <Esc> hit

I insert text at beginning of current line, until <Esc> hit

2. a append text after cursor, until <Esc> hit

A append text to end of current line, until <Esc> hit

3. o open and put text in a new line below current line, until <Esc> hit

O open and put text in a new line above current line, until <Esc> hit

Changing Text

The following commands allow you to modify text.

1. r replace single character under cursor (no <Esc> needed)

R replace characters, starting with current cursor position, until <Esc> hit

2. cw change the current word with new text, starting with the character under cursor,

until <Esc> hit

3. cNw change N words beginning with character under cursor, until <Esc> hit;

e.g., c5w changes 5 words

4. C change (replace) the characters in the current line, until <Esc> hit

cc change (replace) the entire current line, stopping when <Esc> is hit

Ncc or cNc change (replace) the next N lines, starting with the current line, stopping

when <Esc> is hit

Deleting Text

The following commands allow you to delete text.

1. x delete single character under cursor

Nx delete N characters, starting with character under cursor

dw delete the single word beginning with character under cursor

dNw delete N words beginning with character under cursor;

e.g., d5w deletes 5 words

1. D delete the remainder of the line, starting with current cursor position

dd delete entire current line

Ndd or dNd delete N lines, beginning with the current line;

e.g., 5dd deletes 5 lines

Cutting and Pasting Text

The following commands allow you to copy and paste text.

1. yy copy (yank, cut) the current line into the buffer

Nyy or yNy copy (yank, cut) the next N lines, including the current line, into the buffer

2. p put (paste) the line(s) in the buffer into the text after the current line

Other Commands

Searching Text

A common occurrence in text editing is to replace one word or phase by another. To locate instances

of particular sets of characters (or strings), use the following commands.

1. /string search forward for occurrence of string in text

2. ?string search backward for occurrence of string in text

3. n move to next occurrence of search string

N move to next occurrence of search string in opposite direction

Determining Line Numbers

Being able to determine the line number of the current line or the total number of lines in the file

being edited is sometimes useful.

1. :.= returns line number of current line at bottom of screen

2. := returns the total number of lines at bottom of screen

3. ^g provides the current line number, along with the total number of lines, in the file at

the bottom of the screen

Saving and Reading Files

These commands permit you to input and output files other than the named file with which you are

currently working.

1. :r filename<Return> read file named filename and insert after current line (the line with

cursor)

2. :w<Return> write current contents to file named in original vi call

3. :w newfile<Return> write current contents to a new file named newfile

4. :12,35w smallfile<Return> write the contents of the lines numbered 12 through 35 to a

new file named smallfile

5. :w! prevfile<Return> write current contents over a pre-existing file named prevfile