Unix file operation Commnads

appent to file cat >> cat >> file1

combine 2 files cat cat file1 file2 > file3

copy files cp cp myfile copymyfile

create a file cat cat > newfile

edit files vi vi file

list files ls ls bin/

move a file mv mv file1 doc/chapter1

remove a file rm rm unwantedfile

rename a file mv mv oldfilename newfilename

view files cat cat file pg pg file2 file3 more less view view file6 file7

change to another directory cd cd folder1/folder2/

create a directory mkdir mkdir myfolder

find out where you are pwd

go to your home directory cd

remove an emplty eirectory rmdir rmdir junk

Redirection of Output or Input

>	redirects the output of a command to a file
>>	redircts the output of a command to the end of an existing file
<	takes the input of a command form a file, not the terminal

Summary of Basic Commands

cal cal 1 display a calendar
cal [month] year
	month number between 1 and 12		year number between 1 and 9999
Examples:
cal 2012 print calendar for year 2012
cal 1 2012 print calendar for January 2012

Unix command to view files, create files, append to files and combine files

cat cat(1) concatenate and display files

cat [options] [files]

Examples:

cat files read file(s)

cat > file create file (reads form terminal )

cat >> file append to file (reads form terminal )

cat file2 >> file1 appends contents of file2 to file1

cd cd(1) shell built-in functions to change the current working directory

chdir cd(1) shell built-in functions to change the current working directory

chgrp chgrp(1) change the group ownership of a file

chmod chmod(1) change the permissions mode of a file

chown chown(1) change owner of file

clear clear(1) clear the terminal screen

cp cp(1) copy files

date date(1) print and set the date

dc dc(1) arbitrary precision desktop calculator

dos2unix dos2unix(1) convert text file from DOS format to ISO format

eject eject(1) eject media such as CD-ROM and floppy from drive

exit exit(1) shell built-in functions to enable the execution of the shell to advance beyond its sequence of steps

file file(1) file(1B) determine the type of a file by examining its contents

head head(1) display first few lines of files

ls      list the contents of a directory

ls [options] [directories]

the current working directory used if no directories specified

few options:

-a list all entries includeing hidden files (starting with .)

-i print inode numbers

-l long list (mode, links, owner, group, size, timeof last modification, and name

-t sort by modification time

-x multi-column list, sorted across each row

Mail, mailx mailx(1), mail mail(1) rmail interactive message processing system to read mail or send mail to users

mail [options] users

Examples:

mail with no options, to read your mail

mail user to send mail to user

mail user < filename mail a file to another user

mkdir mkdir(1) make directories

more more(1) browse or page through a text file

mv mv(1) move files

pg pg(1) files perusal filter for CRTs

pr pr(1) print files

ps ps(1) ps(1B) display the status of current processes

pwd pwd(1) working directory name

rm rm(1) remove files or directories

rmdir rm(1) remove files or directories

spell spell(1) find spelling errors

tail tail(1) deliver the last part of a file

umask umask(1) shell built-in function to restrict read/write/execute permissions

unix2dos unix2dos(1) convert text file from ISO format to DOS format

vi vi(1) screen-oriented (visual) display editor based on ex

view vi(1) screen-oriented (visual) display editor based on ex

w w(1) who is logged in, and what are they doing

wc wc(1) display a count of lines, words and characters in a file

which which(1) locate a command; display its pathname or alias

who who(1) who is on the system

whoami whoami(1B) display the effective current username

whois whois(1) Internet user name directory service

write write(1) write to another user