Unix Command-Line Processing Unix Directories Files
Unix Command-Line Processing
Useful Commands Permissions tar More Commands Working Remotely
L435/L555
Emacs
Dept. of Linguistics, Indiana University Fall 2014
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What is Unix?
Unix Command-Line Processing Unix Directories Files Useful Commands
Unix is an operating system, like DOS or Windows
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developed in 1969 by Bell Labs
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works well for single computers as well as for servers
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underlying operating system for Macs
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Linux: open source version of Unix (mostly for PCs)
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Directory Structure
Unix Command-Line Processing Unix Directories
directory = folder I
directory structure: tree structure
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Important directories: I I I
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home directory: your private directory (/Users/guest)
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root node: / important directories on a Mac:
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/Applications /Users /Volumes /Volumes/Data/
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Unix
Graphical Representation
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/
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Applications
Users
Volumes
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md7 guest ...
Data
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ar en de multilingual ...
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Useful Commands for Directories I
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list files in current directory:
Unix
ls
Directories
list files with more information:
Files
ls -l
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change directories:
cd I
two possibilities to specify : I
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Unix Command-Line Processing
from root:
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cd /Users/md7 from where we are: cd ../md7 .. means ’go up’
go back to home directory:
cd I
show the directory where you are:
pwd 5 / 22
Useful Shortcuts
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TAB completion If you start typing a command or filename, then press TAB, the shell will complete the word for you – as far as possible.
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Command history
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The shell keeps a history of your commands. To scroll through them, simply press the up arrow key.
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Looking at Files
Unix Command-Line Processing Unix Directories
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display contents of file in terminal:
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cat
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display page by page:
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less
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next page: space bar quit: q go to beginning of file: g go to end of file: G search forward: / + hit return search backward: ? + hit return in search: next found occurrence: n
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Likewise, there is the more command
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Looking at Files More Commands
Unix Command-Line Processing Unix Directories Files
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display beginning of file (normally 10):
head I
display X beginning lines of file:
head -X
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display end of file (normally 10):
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tail I I
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tail -X : display X ending lines tail +X : display all lines starting at X
count number of lines, words, characters in a file:
wc
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Unix
More Useful Commands
Command-Line Processing Unix Directories
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list files that end in ’.txt’:
Files
ls *.txt
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make directory:
Permissions
mkdir subdirectory: mkdir results in your home directory: mkdir
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∼/results
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copy a file from one location to another:
cp I
copy a file to the directory ’results’ in your home directory:
cp dates.txt
∼/results
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More Useful Commands (2)
Unix Command-Line Processing Unix
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sort your file:
sort
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sort (numbers) in numeric order:
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sort -n I
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Directories
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find a word in a file and display all the lines in which it occurred:
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grep
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find a word in a file and display all the lines in which it occurred and save results into a file in your home directory:
grep > ∼/ I
example:
grep linguistic mycorp.txt > ∼/res.txt
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Tangent: How to Find out More
Unix Command-Line Processing Unix Directories Files
What other options are there for sorting? The man command lets you see documentation on whatever unix command is in question I
Find information:
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man man sort | less
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Tangent: grep & egrep
Unix Command-Line Processing Unix Directories Files Useful Commands Permissions
grep is commonly used, but doesn’t offer a full RE syntax I
For that, use egrep (extended grep)
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Bonus: what does grep stand for?
Emacs
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More Useful Commands (3)
Unix Command-Line Processing Unix Directories Files
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delete lines (adjacent) with identical content:
uniq I
delete lines (adjacent) with identical content, but list how many were there:
uniq -c I
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display differences between two files
diff
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Unix
Permission System I
Command-Line Processing
ls -l
-rw-r--r-drwxr-xr-x drwxr-xr-x drwxr-xr-x drwxr-xr-x
Unix
1 15 3 4 35
root root root root root
admin admin admin admin admin
168724 510 102 136 1190
Nov 9 2003 Aug 31 2006 Aug 4 2004 Mar 2 2007 Feb 18 15:23
Jokes.pdf ar cs de en
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change permissions:
chmod : user = u; group= g; others = o; all = a; : read = r; write = w; execute = x; I
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example: give user write permissions for file ’hello.txt’:
chmod u+w hello.txt I
example: deny others write and execute permissions for directory ’test’:
chmod o-wx test 14 / 22
Packing and Unpacking Files
Unix Command-Line Processing Unix
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pack a file:
gzip I
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results in .gz
unpack file:
gunzip .gz I
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’pack’ more than one file:
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tar cvf .tar
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unpack:
tar xvf .tar I
tar and gzip:
tar cvzf .tgz I
unpack:
tar xvzf .tgz
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More on Copy and Move
Unix Command-Line Processing Unix Directories
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copy a file from one location to another:
Files
cp
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move a file from one location to another:
mv I
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rename a file:
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mv
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remove a file:
rm I
remove a directory including contents:
rm -r
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Important Shortcuts in Paths
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.. (go) up one directory . here
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∼ home directory
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Translate
Unix Command-Line Processing Unix Directories Files
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exchange characters for others:
tr ’aeiou’ ’X’ < tr ’aeiou’ ’AEIOU’ <
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collapse characters (squeeze):
tr -s ’J’ < I
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exchange complement of characters for others:
tr -c ’a-z’ ’\n’ < \n is a linebreak
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Putting Commands Together
Unix Command-Line Processing Unix Directories
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< use following filename as input file
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> use following filename as output file
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| use output of preceding command as input for following commands
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example:
cat | tr ’A-Z’ ’a-z’ | sort >
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Remote Login
Unix Command-Line Processing Unix Directories Files Useful Commands
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login: ssh husernamei@hmachinenamei
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e.g.
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ssh
[email protected]
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logout:
exit
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Remote Copy
Unix Command-Line Processing Unix Directories
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to copy a local file to (your home directory) on another machine:
Useful Commands
scp : e.g. scp vm.pos nlp.indiana.edu:
tar
to copy a file from another machine to the current directory:
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scp :/ . e.g. scp nlp.indiana.edu:/Volumes/Data/en/ penntreebankv3/readme.all . (in one line!)
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Emacs
Unix Command-Line Processing Unix Directories
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emacs is a fairly basic text editor that can be run in a window or in the shell to start emacs:
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to quit:
Ctrl-x Ctrl-c I
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save:
Ctrl-x Ctrl-s I
search:
Ctrl-s Other shell editors include vim and nano
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