Unix Commands 1

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UNIX BASIC COMMANDS:LS

Thelscommand lists all files in the directory that match thename. If name is left blank, it will list all

of the files in the directory.

SYNTAX

The syntax for thelscommand is:

ls [options] [names]

OPTIONS

Option Description

-a Displays all files.

-b Displays nonprinting characters in octal.

-c Displays files by file timestamp.

-C Displays files in a columnar format (default)

-d Displays only directories.

-f Interprets eachnameas a directory, not a file.

-F Flags filenames.

-g Displays the long format listing, but exclude the owner name.

-i Displays the inode for each file.

-l Displays the long format listing.


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The syntax for thecatcommand is:

cat [options] [fles]

OPTIONS

Option Description

-e $ is printed at the end of each line. This option must be used with -v.

-s Suppress messages pertaining to files that do not exist.

-t

Each tab will display as I and each form feed will display as L. This option must be used

with -v.

-u Output is printed as unbuffered.

-v Display control characters and nonprinting characters

EXAMPLE

cat fle1

cat fle1 fle2 > all

cat fle1 >> fle2

UNIX BASIC COMMANDS:CD

Thecdcommand changes directory.

SYNTAX

The syntax for thecdcommand is:

cd [dir]


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EXAMPLE

cd tech

cd /tech

UNIX BASIC COMMANDS:MKDIR

Themkdircommand creates a single directories or multiple directories.

SYNTAX

The syntax for themkdircommand is:

mkdir [options] directories

OPTIONS

Option Description

-m mode Sets the access mode for the new directory.

-p If the parent directories don't exist, this command creates them.

EXAMPLE

mkdir -m 444 tech

mkdir -p tech/net/aqs

UNIX BASIC COMMANDS:MVThemvcommand allows you to move and rename files.

SYNTAX

The syntax for themvcommand is:


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mv [options] sources target

OPTIONS

Option Description

-f Forces the move.

-i Prompt for a confirmation before overwriting any files.

EXAMPLE

mv - tech /usr

UNIX BASIC COMMANDS:TELNET

Thetelnetcommand allows you to communicate to another host using the TELNET protocol.

SYNTAX

The syntax for thetelnetcommand is:

telnet [host [port]]

UNIX BASIC COMMANDS:FTP

Theftpcommand allows you to transfer files to and from a remote server.

SYNTAXThe syntax for theftpcommand is:

tp [options] [hostname]

OPTIONS


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Option Description

-d Debugging is enabled.

-g Filename globbing is disabled.

-i Interactive prompting is disabled.

-n When you are initially connecting, auto-login is disabled.

-v Display all responses from the server.

EXAMPLE

tp tech

tp -v tech

UNIX BASIC COMMANDS:KILL

Thekillcommand allows you to kill one process ID or multiple process IDs.

SYNTAX

The syntax for thekillcommand is:

kill [options] Is

OPTIONS

Option Description

-l Lists the signal names.

-signal The signal number of name. Using the signal number of 9, means that the kill is absolute.


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EXAMPLE

kill -! "#$#!

UNIX BASIC COMMANDS:PS

Thepscommand displays active processes.

SYNTAX

The syntax for thepscommand is:

ps [options]

OPTIONS

Option Description

-a Displays all processes on a terminal, with the exception of group leaders.

-c Displays scheduler data.

-d Displays all processes with the exception of session leaders.

-e Displays all processes.

-f Displays a full listing.

-glist Displays data for thelistof group leader IDs.

-j Displays the process group ID and session ID.

-l Displays a long listing

-plist Displays data for thelistof process IDs.


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-slist Displays data for thelistof session leader IDs.

-tlist Displays data for thelistof terminals.

-ulist Displays data for thelistof usernames.

EXAMPLE

ps -e

ps -au%

UNIX BASIC COMMANDS:GREP

Thegrepcommand allows you to search one file or multiple files for lines that contain a pattern. Exit

status is 0 if matches were found, 1 if no matches were found, and 2 if errors occurred.

SYNTAX

The syntax for thegrepcommand is:

grep [options] pattern [fles]

OPTIONS

Option Description

-b Display the block number at the beginning of each line.

-c Display the number of matched lines.

-h Display the matched lines, but do not display the filenames.

-i Ignore case sensitivity.

-l Display the filenames, but do not display the matched lines.


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-n Display the matched lines and their line numbers.

-s Silent mode.

-v Display all lines that do NOT match.

-w Match whole word.

EXAMPLE

grep -c tech fle1

dd commands:

he ddcommand copies a file, convertingthe format of the data in the

process, according to the operandsspecified.

Syntax

dd [OPERAND]...

dd OPTION

Operands

bs=BYTES readand &riteBYTES'(tesat a time )also see ibs=*obs=+

cbs=BYTES convert BYTES'(tes at a time

conv=CONV

S

convert the fle as per the comma separated s(m'ol list, ach s(m'o

ollo&ing* and represents a specifc t(pe o conversion.

ascii

rom 0I0to 0II

ebcdic

rom 0II to 0I0
http://www.computerhope.com/jargon/c/conversi.htmhttp://www.computerhope.com/jargon/o/operand.htmhttp://www.computerhope.com/jargon/r/read.htmhttp://www.computerhope.com/jargon/w/write.htmhttp://www.computerhope.com/jargon/b/byte.htmhttp://www.computerhope.com/jargon/e/ebcdic.htmhttp://www.computerhope.com/jargon/a/ascii.htmhttp://www.computerhope.com/jargon/o/operand.htmhttp://www.computerhope.com/jargon/r/read.htmhttp://www.computerhope.com/jargon/w/write.htmhttp://www.computerhope.com/jargon/b/byte.htmhttp://www.computerhope.com/jargon/e/ebcdic.htmhttp://www.computerhope.com/jargon/a/ascii.htmhttp://www.computerhope.com/jargon/c/conversi.htm


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ibm

rom 0II to alternate 0I0

block

pad ne&line-terminatedrecords &ith spaces to cbs-si3eunblock

replace trailing spaces in cbs-si3e records &ith ne&line

lcase

change upper caseto lo&er case

nocreat

do not create the outputfle

excl

ail i the output fle alread( e%ists

notrunc

do not truncatethe output fle

ucase

change lo&er case to upper case

swab

s&ap ever( pair o input '(tes

noerrorcontinue ater read errors

sync

pad ever( input'lock&ith 56sto ibs-si3e7 &hen used &ith 'lock or

spaces rather than 56s

fdatasync

ph(sicall( &rite output fle data 'eore fnishing

fsync

like&ise* 'ut also &rite metadata,

count=BLOC

KS

cop( onl( BLOCKSinput 'locks

ibs=BYTES read BYTES'(tes at a time )deault. 512+

if=FILE read rom FILEinstead o stdin
http://www.computerhope.com/jargon/n/newline.htmhttp://www.computerhope.com/jargon/t/terminat.htmhttp://www.computerhope.com/jargon/u/uppercase.htmhttp://www.computerhope.com/jargon/l/lowercas.htmhttp://www.computerhope.com/jargon/o/output.htmhttp://www.computerhope.com/jargon/t/truncate.htmhttp://www.computerhope.com/jargon/i/input.htmhttp://www.computerhope.com/jargon/b/block.htmhttp://www.computerhope.com/jargon/n/null.htmhttp://www.computerhope.com/jargon/m/metadata.htmhttp://www.computerhope.com/jargon/s/stdin.htmhttp://www.computerhope.com/jargon/n/newline.htmhttp://www.computerhope.com/jargon/t/terminat.htmhttp://www.computerhope.com/jargon/u/uppercase.htmhttp://www.computerhope.com/jargon/l/lowercas.htmhttp://www.computerhope.com/jargon/o/output.htmhttp://www.computerhope.com/jargon/t/truncate.htmhttp://www.computerhope.com/jargon/i/input.htmhttp://www.computerhope.com/jargon/b/block.htmhttp://www.computerhope.com/jargon/n/null.htmhttp://www.computerhope.com/jargon/m/metadata.htmhttp://www.computerhope.com/jargon/s/stdin.htm


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iag=FLAGS read as per the comma separated s(m'ol list, ach s(m'ol ma( 'e o

append

append mode )makes sense onl( or output7 conv=notruncsuggeste

directuse direct I/8or data

directory

ail unless a director(

dsync

use s(nchroni3ed I/8 or data

sync

like&ise* 'ut also or metadata

fullblock

accumulate ull 'locks o input )i9ag onl(+

nonblock

use non-'locking I/8

noatime

do not update access time

noctty

do not assign controlling terminal rom flenofollow

do not ollo& s(mlinks,

obs=BYTES &rite BYTES'(tes at a time )deault. 512+

of=FILE &rite to FILEinstead o stdout

oag=FLAG

S

&rite as per the comma separated s(m'ol list

seek=BLOC

KS

skip BLOCKSobs-si3ed 'locks at start o output

skip=BLOCK

S

skip BLOCKSibs-si3ed 'locks at start o input

status=no%

er

suppress transerstatistics
http://www.computerhope.com/jargon/i/io.htmhttp://www.computerhope.com/jargon/d/director.htmhttp://www.computerhope.com/jargon/s/symblink.htmhttp://www.computerhope.com/jargon/d/datatran.htmhttp://www.computerhope.com/jargon/i/io.htmhttp://www.computerhope.com/jargon/d/director.htmhttp://www.computerhope.com/jargon/s/symblink.htmhttp://www.computerhope.com/jargon/d/datatran.htm


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:lo& chart

A fowchart is a visual representation o the sequence o steps and decisions needed to

perorm a process. Each step in the sequence is noted within a diagram shape. Steps are

linked by connecting lines and directional arrows. This allows anyone to view the fowchart

and logically ollow the process rom beginning to end


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Unix - The vi Editor

There are many ways to edit files in Unix and for me one of the best ways is

using screen-oriented text editor vi. This editor enable you to edit lines in

context with other lines in the file.

Now a days you would find an improved version of vi editor which is

called VIM. ere !"# stands for Vi IMproved.

The vi is generally considered the de facto standard in Unix editors because

$

"t%s usually available on all the flavors of Unix system.

"ts implementations are very similar across the board.

"t re&uires very few resources.

"t is more user friendly than any other editors li'e ed or ex.

(ou can use vieditor to edit an existing file or to create a new file from

scratch. (ou can also use this editor to )ust read a text file.

*tarting the vi Editor

There are following way you can start using vi editor $

Command Description

vi filename +reates a new file if it already does not exist, otherwise opens

existing file.

vi -R filename pens an existing file in read only mode.

view filename pens an existing file in read only mode.


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ollowing is the example to create a new file testfileif it already does not

exist in the current wor'ing directory $

;vi testfle

s a result you would see a screen something li'e as follows $

Documents

Unix Commands 1