UNIX Utilities Learning Objectives: 1. To understand the some basic utilities of UNIX File 2. To compare UNIX shell and popular shell 3. To learn Input/Output

UNIX Utilities

Learning Objectives:1. To understand the some basic utilities of UNIX

File

2. To compare UNIX shell and popular shell

3. To learn Input/Output Redirection and the Pipe function

COMP111COMP111Lecture 2 / Slide Lecture 2 / Slide 22

UNIX Utilities

Table of Content Getting Started with UNIX Basic UNIX File Utilities UNIX File Utilities – Example The UNIX Shell Popular Shells Utilities for Finding Info Utilities for Interacting with Other Users More Utilities Input/Output Redirection Pipes


Getting Started with UNIX

The machines in CS Lab2 are named csl2su1 .. csl2su40. csl2su3 means “CSLab2, Sun#3” The full machine name for csl2su4 is: csl2su4.cs.ust.hk You can access these computers with telnet from other

computers via the Internet:telnet csl2su4.cs.ust.hk

(from other UNIX computers or even Windows) You need to log in to a UNIX computer with a valid account and

password:UNIX(r) System V Release 4.0 (csl2su4)login: kwchiuPassword:


Basic UNIX File Utilities

ls list files in current directory cat display (concatenate) file more display one screen of file rm remove (delete) a file cp copy source file to target file mv rename or move a file lpr print a file man online UNIX help manual mpage print multiple pages on postscript printer


UNIX File Utilities - Example (1)

$ ls

letter1 secret

$ cat letter1

Ms. Lewinski:

It is getting late. Please order some pizza and stop

by my office. We’ll tidy up a few more things before

calling it a night.

Thanks!

Bill

$ cp letter1 letter2

$ ls

letter1 letter2 secret


UNIX File Utilities – Example (2)

$ mv letter1 letter3

$ ls -F

letter2 letter3 secret/

$ lpr -Pcll3 letter2

$ mpage -Pcll3 letter2

$ rm letter2

$ ls -F

letter3 secret/



$ man ls

Reformatting page. Wait... done

User Commands ls(1)

NAME

ls - list contents of directory

SYNOPSIS

/usr/bin/ls [ -aAbcCdfFgilLmnopqrRstux1 ] [ file... ]

/usr/xpg4/bin/ls [ -aAbcCdfFgilLmnopqrRstux1 ] [ file... ]



DESCRIPTION

For each file that is a directory, ls lists the contents of

the directory; for each file that is an ordinary file, ls

repeats its name and any other information requested. The

output is sorted alphabetically by default. When no argu-

ment is given, the current directory is listed. When

several arguments are given, the arguments are first sorted

appropriately, but file arguments appear before directories

and their contents.

There are three major listing formats. The default format

for output directed to a terminal is multi-column with

--More--(5%)


The UNIX Shell

The UNIX shell listens to what you type and executes commands at your request.

User command:lpr file UNIX

Shell

UNIX

Kernel

Command

Library

ls, lpr, mv, rm,

telnet, netscape,

...

result or status

Printers

Files

Memoryresults (on screen)


Popular Shells

sh Bourne shell (the original shell) csh C-shell (pronounced as “sea shell”) tcshLike csh with more functions (default for our

lab computers) bash “Bourne again” shell ksh Korn shell zsh Z-shell


Utilities for Finding Info (1)

who Who is logged on, where & when

$ whohorner pts/0 Jan 29 09:52 (csz096.cs.ust.hk)clinton pts/1 Jan 29 10:43 (csnt1.cs.ust.hk)

finger A bit more login information

$ fingerLogin Name TTY Idle When Wherehorner Andrew Horner pts/0 12 Fri 09:52 csz096.cs.ust.hkclinton Bill Clinton pts/1 121 Fri 10:43 csnt1.cs.ust.hk


Utilities for Finding Info (2)

write Send message to another user$ whoamihorner$ write clintonBill, you’ve been idle for a long time! What are you doing? [hit CTRL-D to end write message]$ ---------------------------------------------------------$ whoamiclinton Message from horner on csz096.cs.ust.hk [ Fri Jan 29 20:18:47

. Bill, you’ve been idle for a

long time! What are you doing? <EOT>$


Utilities for Interacting with Other Users: talk (1) talk chat for UNIX

$ whoamihorner$ talk clinton[Waiting for your party to respond][Connection established]Hi Bill, what’s up?

+-----------------------------------------------------+Hi! I’m a little busy right now. Is it okay if I call you back latter?


Utilities for Interacting with Other Users: talk (2)$ whoamiclinton$ Message from [email protected] at 20:41 ...talk: connection requested by [email protected]: respond with: talk [email protected]$ talk [email protected][Waiting for your party to respond][Connection established]Hi! I’m a little busy right now. Is it okay if I call you back latter?

+-----------------------------------------------------+Hi Bill, what’s up?


More Utilities (1)

echo date head tail grep sort uniq


More Utilities (2)

echoDisplay command line input to screen$ echo Hi, I am Bill, the President of the US!

Hi, I am Bill, the President of the US!

date Print the date and time$ date

Wed Feb 3 12:13:07 HKT 1999


More Utilities (3)

headDisplay first few lines of file$ head -2 letter3Ms. Lewinski:It is getting late. Please order some pizza and stop

tailDisplay last few lines of file$ tail -2 letter3Thanks!Bill

grep Find a pattern in a file$ grep ”some pizza” letter3It is getting late. Please order some pizza and stop


More Utilities (4)

sort Sort the lines in lexical order $ sort letter3BillIt is getting late. Please order some pizza and stopMs. Lewinski:Thanks!by my office. We'll tidy up a few more things beforecalling it a night.

$ sort -r letter3calling it a night.by my office. We'll tidy up a few more things beforeThanks!Ms. Lewinski:It is getting late. Please order some pizza and stopBill


More Utilities (5)

uniqDisplay file with duplicate adjacent lines removed

$ cat namesBill ClintonBill GatesBill GatesBill ClintonMonica Lewinski

$ uniq namesBill ClintonBill GatesBill ClintonMonica Lewinski


Input/Output Redirection (1)

On UNIX, the standard input (stdin) is the keyboard; the standard output (stdout) is the display screen.

$ sort

waits for you to type in the data from the keyboard and displays the sorted data on the screen.

sort

keyboard

display



Using the “>” character after a command to redirect output to a named file:

$ sort names > names.sort$ uniq names.sortBill ClintonBill GatesMonica Lewinski

This will create a file test:$ cat > testtype line 1type line 2<ctrl-d> $ cat testtype line 1type line 2

uniq

display

sort

names

names.sort



Using the “>>” character after a command to redirect output to APPEND to a named file:

Typing to the end of a file

$ cat >> testtype line 3type line 4<ctrl-d>

$ cat testtype line 1type line 2type line 3type line 4

Append file1 to file2

$ cat file1 >> file2



Using the “<” character after a command to redirect input from a named file:

$ uniq < names.sort

This is the same as:

$ uniq names.sort

Using input and output redirection together:

$ sort < names > names.sort

uniq

display

sort

names

names.sort

names.sort


Appending and Pattern Matching

We have seen input redirection (cat <file) and output redirection (cat >file). We can also append to a file using >>

$ date > file$ who >> file

Simple file pattern matching The * pattern matches any number of characters:

$ ls -l letter*

lists all files in the working directory that start with “letter” The ? pattern matches any single character:

$ ls -l letter?

lists all files in the working directory that start with “letter” followed by exactly one character.


Pipes (1)

The standard output of a program can be “piped” into the standard input of another program:

$ sort names | uniq

Bill Clinton

Bill Gates

Monica Lewinski

uniq

display

sort

names


Pipes (2)

Several pipes can be connected:$ sort names | uniq | grep "Bill"

Bill Clinton

Bill Gates

Pipes and I/O redirection can be used together:$ sort -r names | uniq >names.rev

$ cat names.rev

Monica Lewinski

Bill Gates

Bill Clinton

Documents

UNIX Utilities Learning Objectives: 1. To understand the some basic utilities of UNIX File 2. To compare UNIX shell and popular shell 3. To learn Input/Output