Unix Reference

Change Password

Type passwd, and answer the system prompts for old password, new password, and verification of new password.

Help

• help on a certain subject: man -k subject
• help on a certain command: man command
• online information: info

Account Information

• To check quota: quota -v
• To check print credits: ljstat

Files

The characters ? and * are used for pattern matching. A ? matches any single character, and a * matches an arbitrary number of characters.

Creating

• create file: see Editing

Removing/Renaming/Moving/Copying

• remove file: rm filename
• rename file: mv filename newname
• move file to another directory: mv filename dirname
• copy file to another filename: cp filename newfile
• copy file to another directory: cp filename dirname

Listing

• list file(s): ls filename(s)
• list files sorted by time of last modification: ls -t filenames

Directories

Like filenames, directories use ? and * as pattern matching characters (see Files). The current directory and parent directory, are named . and .. respectively.

Creating/Traversing

• create/make a directory: mkdir dirname
• change directory to home directory: cd
• change directory to parent directory: cd ..
• change directory to another directory: cd dirname
• print working directory: pwd

Removing/Renaming/Moving/Copying

• remove empty directory: rmdir dirname
• remove directory and contents: rm -r dirname
• rename directory, or move directory to another directory: mv dirname newdir
• copy directory and contents to another directory: cp -r dirname dir

Listing

• list current directory contents: ls
• list directory contents: ls dirname
• list directory contents sorted by time of last modification: ls -t dirname

I/O Redirection

The standard input/output/error of a command, normally associated with the terminal, may be redirected by appending one the following to the command line:

• open file as standard input: < filename
• open file as standard output: > filename
• open file as standard output and standard error: >& filename
• append standard output to file: >> filename
• append standard output and standard error to file: >>& filename
• pipe standard output of command1 to standard input of command2: cmd1 | cmd2

Editing

• create/edit file - jove editor: jove filename
• create/edit file - visual editor: vi filename
• create/edit file - emacs editor: emacs filename
• create/edit file - line editor: ex filename

Printing

• print text file on screen: more filename
• print text file on screen: less filename
• print text file on laser printer: lw -Pprintername filename
• print tex document on laser printer: lw -d -Pprintername filename
• print postscript document on laser printer: lw -ps -Pprintername filename
• check laser printer queue: lwq -Pprintername
• remove printjob from laser print queue: lwrm -Pprintername jobnumber

Formatting Documents

• format a tex document: tex filename
• format a latex document: latex filename

T_EX and laT_EX files must have .tex as a filename extension. T_EX and laT_EX produce files with .dvi as a filename extension.
To view a .dvi file: xdvi filename

Electronic Mail

• read mail: pine
• Shortcut: at $prompt, to send mail to a address: pine address
• Shortcut: at $prompt, to send mail to multiple addresses: pine address1 address2 address3
• mail a file to some address: mail address < file

News

• read/post news: tin
• post news: Pnews

Languages and Compilers

• compile C lanuage source file: gcc filename
• compile C++ lanuage source file: g++ filename
• compile java lanuage source file: javac filename
• run java file on java virtual machine: java filename
• compile Fortarn lanuage source file: f77 filename
• compile Pascal lanuage source file: pc filename
• run Common Lisp interpreter: cl
• Awk pattern scanning and processing language: gawk -f programfile

C, Fortran, Java and Pascal source files must have the extensions .c, .f, .java and .p respectively.

Commands

• calulator: bc
• monthly calendar: cal month year
• yearly calendar: cal year
• current date and time: date
• show differences between two files: diff file1 file2
• display information about a user: finger username
• file transfers to/from a remote host: ftp hostname
• find lines matching a specific string: grep string file(s)
• find lines not matching a specific string: grep -v string file(s)
• show the first num lines of filename: head -num filename
• view online manual pages: man command
• login to a remote unix host: rlogin hostname
• execute a command on a remote unix host: rsh host command
• spelling checker: spell filename
• show the last num lines of filename: tail -num filename
• talk to another user: talk username
• connect to a remote host: telnet hostname
• display information on the top CPU processes: top
• show how long the system has been up: uptime
• display number of lines, words, and character in a file: wc filename
• show who is on the system: who