Quick Unix Tutorial

Quick Unix Tutorial

Examples of Basic Commands

Action	Command	Examples
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 pg more less view	cat file pg file2 file3 view file6 file7

Directories	Command	Examples
change to another directory	cd	cd example/first/
create a directory	mkdir	mkdir example1
find out where you are	pwd	pwd
go to your home directory	cd	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

• apropos  locate commands by keyword lookup
• arch  display the architecture of the current host
• cal  display a calendar
  cal [month] year
  
  • month   number between 1 and 12
  • year      number between 1 and 9999
  Examples:
  cal 1996      print calendar for year 1996
  cal 1 1997   print calendar for January 1997
  
• cancel  send/cancel requests to an LP print service
• cat  concatenate and display files (To view files, create files, append to files and combine files)
  cat [options] [files]
  Examples:
  cat files                read file(s)
  cat > file              create file (reads form terminal; terminate input with ^D)
  cat >> file            append to file (reads form terminal; terminate input with ^D)
  cat file2 >> file1   appends contents of file2 to file1
  
• cd  shell built-in functions to change the current working directory
• chdir  shell built-in functions to change the current working directory
• chgrp  change the group ownership of a file
• chmod  change the permissions mode of a file
• chown  change owner of file
• clear  clear the terminal screen
• cp  copy files
• date  print and set the date
• dc  arbitrary precision desktop calculator
• dos2unix  convert text file from DOS format to ISO format
• eject  eject media such as CD-ROM and floppy from drive
• exit  shell built-in functions to enable the execution of the shell to advance beyond its sequence of steps
• file  determine the type of a file by examining its contents
• head  display first few lines of files
• lp  send/cancel requests to an LP print service
• lpstat  print information about the status of the LP print service
• ls  list the contents of a directory
  ls [options] [directories]
  the current working directory used if no directories specified
  A 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, mail 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  make directories
• more  browse or page through a text file
• mv  move files
• nispasswd  change NIS+ password information
• page  browse or page through a text file
• pg  files perusal filter for CRTs
• pr  print files
• ps  display the status of current processes
• pwd  working directory name
• rm  remove files or directories
• rmdir  remove files or directories
• spell  find spelling errors
• tail  deliver the last part of a file
• umask  shell built-in function to restrict read/write/execute permissions
• unix2dos  convert text file from ISO format to DOS format
• vi  screen-oriented (visual) display editor based on ex
• view  screen-oriented (visual) display editor based on ex
• w who is logged in, and what are they doing
• wc  display a count of lines, words and characters in a file
• which  locate a command; display its pathname or alias
• who  who is on the system
• whoami  display the effective current username
• whois  Internet user name directory service
• write write to another user