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Command Description

~~~~~~~ ~~~~~~~~~~~

awk Search for a pattern within a file. Includes

a built-in programming language.

bdiff Compares two large files.

bfs Scans a large file.

cal Displays a calendar.

cat Concatenates and prints files.

cc C compiler.

cd Change directory.

chgrp Changes a file's group ownership.

chmod Changes a file's access permissions.

chown Changes the individual ownership of a file.

cmp Compares two files; diplays the location (line

and byte) of the 1st difference between these.

comm Compares two files so as to determine which

lines are common to both.

cp Copies a file to another location.

cu Calls another UNIX system.

date Returns the date and time.

df Displays free space in the file system.

diff Displays the differences between two files

or directories.

diff3 Displays the differences between three files

or directories.

du Reports on file system usage.

echo Displays its argument.

ed Text editor.

ex Text editor.

expr Evaluates its argument which is generally

a mathematical formula.

f77 FORTRAN compiler.

find Locates the files w/ specified characteristics.

format Initializes a floppy disk.

grep Searches for a pattern within a file. (see awk)

help Salvation.

kill Ends a process.

ln Used to link files.

lpr Copies the file to the line printer.

ls Displays info. about one or more files.

mail Used to receive or deliver e-mail.

mkdir Creates a new directory.

more Displays a long file so that the user

can scroll through it.

mv Used to move or rename files.

nroff Used to format text.

ps Display a process's status.

pwd Display the name of the working directory.

rm Removes one or more files.

rmdir Deletes one or more directories.

sleep Causes a process to become inactive for a

specified length of time.

sort Sort and merge one or more files.

spell Finds spelling errors in a file.

split Divides a file.

stty Display or set terminal parameters.

tail Displays the end of a file.

troff Outputs formatted output to a typesetter.

tset Sets the terminal type.

umask Allows the user to specify a new creation


uniq Compares 2 files. Finds and displays lines

in one file that are unique.

uucp UNIX-to-UNIX execute.

vi Full screen editor.

wc Displays details in the file size.

who Info. on who else be online.

write Used to send a message to another user.

- - Following the Summary is a more in-depth look at each

of the commands already listed.

awk program filenames

awk -f programfilenames filenames


The [awk] utility can be used to find any lines in a file which

match a certain pattern; once found, these lines can be processed.

In the first configuration, the program that [awk] is to

execute is specified in the command line. In the second,

the program is stored as the file given in programfilename.

The -f option instructs [awk] to read this file.

[bdiff] is used to compare files too large for [diff]. See

[diff] for the format.

bfs filename


[bfs] is used to scan a large file to determine where to split

it into smaller files.

cal 01-12 (month) 0-9999 (year)


[cal] utility can be used to display a calendar of any year

from 0 to 9999 AD, and any or all of the twelve months.

cat filename


[cat] can be used to examine a short file. See [more] for

lengthier files.



The [cc] command changes the entire current line, or a group

of lines starting with the current line. [number] represents

the number of old lines to be deleted.

cd directory name


The [cd] command causes the current working directory to be

changed. The [directory name] can be either a full or partial

path name.

chgrp groupname filename


This command changes the group ownership of a file.

chmod {ugoa} {+-} {rwx}


The [chmod] utility changes a file's access permissions. [u]

specifies the user or owner's login name, [g] specifies a group

and [o] indicates all others. [a] indicates the user, group,

and all others; c'est the default. [+] adds permission; [-]

deletes it. [r] indicates read, [w] write, and [x] execute.

chown individualname filename


[chown] changes the individual ownership of a file (see chgrp).

cmp filename1 filename2


[cmp] is one of the four principle UNIX file comparison utilities.

It compares 2 files, and returns the positions where they differ.

comm -options filename1 filename2


The [comm] utility, in comparing two files, produces three

columns of output. The first contains lines unique to the

first file, the second, lines unique to the second, and the

third column, lines common to both files. By placing the

numbers [1], [2], and/or [3] in the [options] position, any

one (or more) of these columns can be suppressed.

cp sendingfile receivingfile


The [cp] command copies a file. [sendingfile] is the file to be

copied, [receivingfile] is the file to which it is copied.

diff [options] filename1 filename2


Again, a file comparison utility. However, with [diff], the

differences are displayed as instructions that can be used

to edit the files so that they are identical.

diff3 filename1 filename2 filename3


Similar to [diff], [diff3] is unique in that it can compare

three files. Gee.

ed filename


One of the UNIX's three editing utilities, [ed] is a basic line

editor. I'm sure there are other files that will explain how

to use [ed]. Thus, I'll confine myself to a rough outline:

e filename ........... edit a different file

f filename ........... changes the currently specified file.

h .................... provides explanation of errors.


text ................. inserts text before the current line.

line,linel ........... lists the specified lines.

line,linen ........... displays specified lines, preceded by

their line numbers.

q .................... exit from [ed]

w .................... writes buffer to current filename.

+ or - ............... +number of lines closer to end

-number of lines closer to beginning.

expr formula


Utility which evaluates an expression.

find directory searchcriteria parameter actioncriteria parameter


The [find] utility can be very useful indeed, especially when

confronted by a UNIX with countless files. Basically, this

command finds files which meet certain criteria, and then

performs an operation (such as printing the files). Search

criteria consists of the following:

Criteria Parameter Description

~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~~

-name filename Files whose names match [filename]

will meet this criteria.

-type filetype Files whose type matches that specified

[b] block special will meet criteria.

[c] character spec. file

[d] directory file

[f] plain file

-links +/- x Files with # of links indicated by

+ or - x meet this criteria.

-user login name Files belonging to user with given

or user ID # login name or ID # meet criteria.

-group group name Files belonging to group with given

or group ID # group name or ID # meet this criteria.

-size + or - x Files greater than +x bytes or less

than -x bytes meet this criteria.

-atime + or - x Files not accessed within +x days,

accessed within -x days, or acc-

essed x days ago meet criteria.

-mtime + or - x Files NOT modified within +x days,

modified within -x days, or modified

x days ago will meet this criteria.

-newer filename Files modified more recently than

[filename] meet this criteria.

Action Criteria " "

~~~~~~~~~~~~~~~ ~ ~

-print - When search criteria are met, path

name of the file is displayed.

-exec command{ }\; Executes given command when search

criteria are met. { } indicates file-

name, [\;] ends the command.

-ok command{ }\; Exactly like -exec, except user is

prompted [y] or [n] before command.

grep -options searchstring filenames


Another search command, this for a particular string of chars.

ln original new


[ln] establishes a file link. For this utility, [original] repre-

sents the filename to be linked, [new] the filename of the new

link to the original.

[ls] provides directory information. [ls -l/] displays a more

complete version of the info. list.

mail username username


This utility allows e-mail to be sent to other system users.



Simply typing [mail] checks the user's own mailbox.

When sending mail, several items must be set:

~s text ............ sets the subject field

~c user names ...... sends other users carbon copies of mail

m user names ....... activates the compose mode, with the

specified users as the message's recipients.

~h ................. displays and allows editing of all headers.

^D ................. ends message editing; sends mail.

~r filename ........ places file in body of message (keen command)

Reading One's Own Mail:

h number or range ....... causes specified headers to be displayed

p message # ............. displays entire message

d number or range ....... deletes specified messages

u number or range ....... undelete specified mail during SAME

mail session (messages removed after q)

q ....................... leave the post office

mkdir directoryname


[mkdir] allows creation of a subdirectory, for your dining


more filename


For longer files, [more] is a convenient utility. It will display

the first screen of file data and then stop, allowing the user

to control scrolling henceforth.

mv oldfilename newfilename


The [mv] utility can be used simply to rename a file, or...

mv filea fileb... directory


[mv] can also be used to move files to a new directory, provided

the directory exists, and you have write access to it.

ps -options


The [ps] command, by itself, displays the status of each active

process controlled by your terminal. This status report includes

the Process Identification Number (PID), the terminal (TTY), the

time the process has been executing (TIME), and the command line

used to execute the process (CMD).

[ps]'s three options include -a (displays info. on active processes

controlled by any terminal), -x (info. on ALL active processes), and

-l (an extensive status report on all active processes).



[pwd] command displays the present working directory.

rm filename


[rm] removes a file. More than one file can be specified.

rmdir directoryname


This utility removes a directory, an EMPTY directory (save the

hidden files).

sleep seconds


The [sleep] utility causes a process to become inactive for a

certain period of time. Max. seconds is 65,536 (about 18 hrs).

sort -options filenames


[sort] merges and sorts files. Without options, [sort] orders

files by the ASCII codes of the characters at the beginning

of each line. Options include -b (leading blanks ignored), -d

(only letters, digs, and blanks considered; "dictionary sort"),

-f (case ignored), -n (numerical sort [for numerical data]), and

-r (a reverse sort).

split -size original resulting


[split] divides a large file into smaller ones. [size] refers to

the number of lines the resulting files contain, [original] is

the name of the orig. file, and [resulting] represents the

prefix name assigned to the newly created files.

umask ugo


[umask] changes the file CREATION mask (see [chmod] for already

existing files). Here, [u] represents the owner's access

permission, [g] the group's a.p., and [o] the a.p. for all others.

[uucp] (UNIX to UNIX copy) can be used to send files to a

remote UNIX, or retrieve files from the remote system.

Other UNIX comm commands include [cu] (which establishes contact

with another system), and [uux] (UNIX to UNIX execute; allows

commands to be executed on a remote system).

wc -options filenames


The [wc] utility displays file-size information. This includes

the number of lines, words, and characters. By chosing the

-l, -w, or -c options, the information can be limited to only

line, word, or character number.



A very useful command (which some systems respond to even before

a user is actually logged on), [who] displays a list of users

currently online. This list includes the user's name, terminal

device # (tty), and the log-in time. [who am i] displays info.

only on the user who executed the command.