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Linux Commands

Notes on various commands for Linux

Contents

Compression

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zip/unzip

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list files in pictures.zip: 

unzip -l pictures.zip

extract picture01.bmp from pictures.zip: 

unzip pictures.zip picture01.bmp

extract all files from pictures.zip: 

unzip pictures.zip

Create archive of all .bmp files in directory:

zip pictures.zip *.bmp

Recursively create archive of all files and directories in dirname:

zip archive.zip dirname

tar

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extract foo.tar: 

tar -xf foo.tar

extract foo.tar.gz: 

tar -xzf foo.tar.gz

extract foo.tar.bz2: 

tar -xjf foo.tar.bz2

extract file.txt from foo.tar.gz 

tar -xzf foo.tar.gz file.txt

create bzipped tar archive of directory bar called foo.tar.bz2: 

tar -cjf foo.tar.bz2 bar/

create archive of .ttreerc and websrc/ in ttsite.tar.bz2: 

tar -cjf ttsite.tar.bz2 .ttreerc websrc/

list files in ttsite.tar.bz2: 

tar -tf ttsite.tar.bz2

extract directory data/vmware/C2000 and contents from machines.tar.bz2: 

tar -xjf machines.tar.bz2 data/vmware/C2000

gzip

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Compress filename into filename.gz

gzip filename

Uncompress filename.gz to filename

gunzip filename.gz

Uncompress filename.gz to STDOUT

zcat filename.gz

bzcat

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Search for pattern in bzip file

bzcat archive.bz2 | grep pattern

Files and Directories

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deleting

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prompt before deleting all .doc files in current directory

rm -i *.doc

delete a file making it practically unrecoverable

shred -n100 -u -v -z topsecret.doc

list files

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List files sorted by size, largest first

ls -lS *

List files sorted by size, smallest first

ls -lSr *

List files sorted by modified time

ls -lt *

cut

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Print first character on each line in filename: 

cut -c1 filename

Print first five characters on each line in filename: 

cut -c1-5 filename

Print fifth field in comma delimited file: 

cut -d, -f5 filename

Use 'stat' for information about a files attributes. 'file' for information about the file type.

rename

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Rename banner01,02,..,0n.jpg files to header01,02,..,0n.jpg: 

rename banner header *.jpg

rename files from .html to .tt2: 

rename .html .tt2 *.html

grep

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Exclude a pattern from search: 

grep -v 'pattern' filename

Search for pattern recursively, printing line number in file: 

grep 'pattern' directory -r -n

Search for pattern recursively, printing filename only if found: 

grep 'pattern' directory -r -l

Search for pattern recursively, printing filename only if not found: 

grep 'pattern' directory -r -L

find

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Find all files and directories named index.html in myweb directory and subdirectories

find ~/myweb -name index.html

Find all files and directories with SQL in their name in the myweb directory and subdirectories

find ~/myweb -name *SQL*

Find only files with SQL in their name

find ~/myweb -name *SQL* -type f

Find only directories with SQL in their name

find ~/myweb -name *SQL* -type d

Find files named *.tt2 and execute 'stat' command

find ~/myweb -name *.tt2 -type f -exec stat '{}' \;

Find files ending with '~' and prompt to execute 'rm' command

find ~/myweb -name '*~' -type f -ok rm '{}' \;

Count all .html files in myweb directory

find ~/myweb -name *.html | wc -l

List all .html files in alphabetical order by filename

find ~/myweb -name *.html -exec basename '{}' \; | sort

Networking

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ssh

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Synchronise files from /home/dr00 on remote machine to /home/dr00 on local machine: 

rsync -avz 192.168.1.5:/home/dr00/ /home/dr00

Synchronise multiple directories from /home/dr00 to another path. Creates each destination directory on the source:

rsync -avz /home/dr00/myweb /home/dr00/Pictures \
/home/dr00/Music /home/dr00/Videos /media/disk/

use ssh to run remote X11 programs: 

ssh -Y user@hostname

netstat

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Use netstat to identify underlying application and PID per port: 

netstat -anpt

Use netstat to identify listening udp and tcp ports: 

netstat -utln

Use netstat to identify connected udp and tcp ports: 

netstat -ptu

Use netstat to identify listening and connected udp and tcp ports: 

netstat -aptu

lsof

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Use lsof to identify underlying application and PID by port: 

lsof -i:5353

redirecting input and output

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run command and redirect output and errors to different files: 

cmd 1>out.txt 2>err.txt

run command and redirect output and errors to same file: 

cmd 1>out.txt 2>&1

run command, leave STDOUT and STDIN untouched, but capture all output to a file: 

cmd | tee out.txt

Subversion

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checkout the code for Authentication part of the Catalyst Tutorial: 

svn co http://dev.catalyst.perl.org/repos/Catalyst/tags/examples/Tutorial/MyApp/5.7/Authentication MyApp

Cron

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The MAILTO environment variable can be set to either a local account, or a valid email address. To send to multiple emails, separate the addresses with a comma

MAILTO=user1@abc.com,user2@abc.com

Crontab entries take the form: min hour monthday month weekday 'command'. Weekdays can be specified as numbers or 3-digit abbreviations: 0 to 6 or sun to sat. A percent sign in the command will be replace with a new line. Examples:

tidy

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Tidy up sloppy html

tidy index.htm > index.html

List errors and warnings for html file

tidy -eq index.htm

List errors and warnings for directory tree of html files

find myweb/html -name '*.html' -print -exec tidy -eq '{}' \;"

xchat

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Connect to an IRC channel

xchat --url=//irc.perl.org/catalyst

wget

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Collect all the css files from a website:

wget -r -nd -Acss http://home.clara.net/