Appendix B
UNIX EXERCISES
- 1. About This Book
- a. What part of UNIX manages the computer system's
resources?
- b. What function does the ksh perform?
- c. What 5 requirements do you need to fill before using
UNIX?
- 2. A Sample Session with UNIX User Commands
- a. Which command do you use to reset your "kill
character" and "Backspace" keys?
- b. Name the three types of standard I/O.
- c. How do you return to your HOME directory?
- d. What keys abort a program?
- e. List 10 common commands in UNIX.
- 3. System Overview
- a. What is the basic philosophy of the UNIX Operating
System?
- b. What does multitasking mean?
- c. What does multiuser mean?
- d. What are four characteristics of the UNIX file
system?
- e. What are the three types of files used in a UNIX file
system?
- f. What two functions does the shell perform?
- 4. alias/unalias
- a. What is the purpose of the alias command?
- b. What is the difference between csh and
ksh aliasing command formats?
- 5. apropos
- a. Why might you use the apropos command?
- b. Write the command to find information about line
editors on UNIX.
- 6. awk/nawk
- a. List three uses of the nawk program.
- b. List five features of nawk.
- c. What does the nawk '{ print }' file command
do?
- d. Write a program to print a header, the /etc/group
file, and a footer.
- e. How would you search for the pattern "tom" in the
first field of input?
- f. What is the syntax for accessing the 10th element of
an array named NAMES?
- g. Write the nawk script to display the first and
fifth fields of the /etc/passwd file. Field one should be left justified in a
10-column output field. Field five should be left justified in a 40-column
output field.
- 7. banner
- a. What is the function of the banner
command?
- b. What options are used with the banner
command?
- c. What is one common use of the banner
command?
- 8. basename
- a. What functions are performed by the basename
command?
- b. Why might you use the basename command in a
shell script?
- 9. bg
- a. What is the purpose of the bg command?
- b. Write the command to place job 2 into background
processing.
- 10. cal
- a. What does the cal command produce?
- b. What does the command cal 99 produce?
- 11. calendar
- a. What service does the calendar command
provide?
- b. List the date formats recognized by the
calendar program.
- c. What does the - option cause to happen?
- 12. cancel
- a. What two functions are performed by the cancel
command?
- b. Why might you use the cancel command?
- c. Write the command line to cancel print job
"imagen-915."
- 13. cat
- a. List six uses of the cat command.
- b. How can you stop and start scrolling?
- c. Write the command to combine file1 and file2 into
file3.
- 14. cd
- a. What is the purpose of the cd command?
- b. Write the command to change directories to your parent
directory.
- c. Write the command to return to the previous
directory.
- d. Write the command to change to the user "njf" HOME
directory.
- 15. chfn
- a. Why might you use the chfn command?
- b. What information is changed by the command?
- c. Write the alternate format of the chfn
command?
- 16. chgrp
- a. What is the function of the chgrp command?
- b. Why might you use the chgrp command?
- c. Write the command to change all files in your HOME
directory to the "mkt" group.
- 17. chmod
- a. What is the purpose of the chmod command?
- b. Write the symbolic mode command to change the
permissions on file1 to read and write for all users.
- c. Write the previous command using absolute modes.
- 18. chown
- a. What is the function of the chown command?
- b. List two reasons for using the chown
command.
- c. Write the command to change the ownership of the
present working directory to "tina."
- 19. clear
- a. What is the function of the clear command?
- b. Why might the clear command not work
properly?
- 20. cmp
- a. What is the purpose of the cmp command?
- b. What is the return code if the files are
identical?
- c. Write the command to compare the standard input to
file1.
- 21. col
- a. What is the function of the col command?
- b. When might you use the col command?
- c. Write the command to use the col command with
the cat file1 command.
- 22. comm
- a. List three functions the comm command
performs.
- b. Write the command to display the lines only found in
the second file.
- c. Explain what text is displayed by the comm -3 file1
file2 command.
- 23. Commands
- a. What is the format for a simple UNIX command?
- b. What signifies a parameter to be an option instead of
an argument?
- c. What must precede an option or group of options?
- d. What does a dash preceded and followed by blanks
signify to a command?
- e. What are the two types of commands in UNIX?
- f. What is the normal return code for a command that
completed successfully?
- 24. cp
- a. List the four uses of the cp command.
- b. Define source file and destination file.
- c. Explain the command cp file1 /etc/tty.
- d. Explain the command cp file1 file1.
- 25. cpio
- a. What are the functions of the cpio
command?
- b. What other UNIX command is often used with cpio
when working with directory structures?
- c. Write the command to copy all of the files in your
HOME directory to the /tmp directory.
- 26. crontab
- a. What is the purpose of the crontab
command?
- b. Write the cron command line to execute a command on
Mondays and Fridays at 10:00 A.M., 2:00 P.M., and 4:00 P.M.
- c. Where is the standard output from your crontab
commands sent if you do not redirect it?
- d. Write the commands required to create a crontab file
and place it in the cron directory.
- 27. crypt
- a. What is the function of the crypt command?
- b. Can "root" (the super-user) read your encrypted
file?
- c. Write the command to encrypt file1. You want to be
prompted for the encryption key.
- 28. csplit
- a. What does the csplit command do?
- b. What are the uses of the csplit command?
- c. Write the command to split file1 at each occurrence of
" (.*)."
- 29. cut
- a. What two modes of cutting are performed by
cut?
- b. Write the command to cut fields 1 and 5 from the
/etc/passwd file.
- c. What causes the error message "line too long" to be
displayed?
- 30. date
- a. Can you (a normal user) change the system date?
- b. What is the default output format of the date
command?
- c. How do you display only the hours and minutes? (SV
only)
- 31. dd
- a. What are the two main functions of the dd
command?
- b. List five types of conversions the dd command
performs.
- c. Write the command to convert ASCII input to EBCDIC
output.
- 32. df
- a. What is the purpose of the df command?
- b. Write the command to display only the /usr filesystem
information.
- 33. diff
- a. What does the diff command do?
- b. How do you make diff ignore blanks in the
input?
- c. Explain the command diff - file2.
- 34. dircmp
- a. What is the function of the dircmp
command?
- b. Explain the output of the first listing generated by
dircmp.
- c. What command makes the output listings easier to read
on your screen?
- 35. dirname
- a. What is the purpose of the dirname
command?
- b. When might you use the dirname command?
- 36. dirs
- a. What does the dirs command display?
- b. Which shell supports the dirs command?
- c. What command must be used before the dirs
command becomes useful?
- 37. du
- a. What is the purpose of the du command?
- b. How do you display only the summary for all files and
directories in your present working directory?
- 38. echo
- a. What are 5 uses of the echo command?
- b. Does the BSD version support escape sequences?
- c. What is equivalent to the -n option on the System V
version?
- 39. ed
- a. How does ed differ from a full screen editor
like vi?
- b. Write the command to edit/create file
myfile.
- c. What are the two modes of operation within
ed?
- d. What is a regular expression?
- e. Write the global search command to locate all empty
lines and display the line number.
- f. How do you enter text into myfile?
- g. How do you return to the ed prompt from insert
mode?
- h. How do you display all lines within the buffer?
- 40. egrep
- a. What is the function of the egrep command?
- b. In what situation will a given pattern not be
located?
- c. How do you display lines that do not match the given
string?
- 41. env
- a. What are the two purposes of the env
command?
- b. What happens if no arguments are given on the
env command line?
- c. Write the command to start a new sh without
passing the current environment.
- 42. eval
- a. What does the eval command force the shell to
do?
- b. Explain the command eval echo '$'$X, where
X=FILE.
- 43. ex
- a. What is the function of the ex command?
- b. How do enter full screen mode?
- c. How do you return to ex mode to perform
multiple commands?
- d. Write the command to mark a position in the buffer as
mark "a."
- e. What address command returns you to mark "a"?
- f. Write the command to change all occurrences of "form"
to "from" and have the editor request confirmation before making the
change.
- g. Explain the command !$sort -u, assuming you are
on the first line of the buffer.
- h. How do you write the current line to a file named
"hold.one"?
- 44. exec
- a. What are the purposes of the exec command?
- b. Write the command to overlay the current shell with
the csh.
- 45. exit/logout
- a. What does the exit command do?
- b. What keystroke performs the same function?
- c. What does logout do that exit does
not?
- 46. expand/unexpand
- a. Explain the expand command.
- b. How do you convert tabs to only four spaces?
- 47. export
- a. What is the purpose of the export command?
- b. What does the export command do if you run it
without arguments?
- c. Why is the export command important?
- 48. expr
- a. What are the four types of operations handled by
expr?
- b. Write the command to delete the first letter from the
value of $X.
- c. Write the command to return the length of a string in
$STR.
- d. What commands in the ksh have replaced the
expr command?
- 49. false
- a. What is the function of the false command?
- b. What is the return code of the false
command?
- 50. fc/!
- a. Describe three uses of the fc command.
- b. What happens when you press Escape and type a
v?
- c. How do you execute the last command that began with
"ls"?
- d. What does the !! command do?
- e. Write the command to execute the last command that
started with "vi."
- 51. fg
- a. What is the purpose of the fg command?
- b. Which shells and operating systems support the
fg command?
- c. Write the command to bring job 3 to the
foreground.
- 52. fgrep
- a. Why might you use the fgrep command instead of
grep?
- b. How do you search for uppercase and lowercase letters
simultaneously?
- c. What option prevents diagnostic messages from being
displayed?
- 53. file
- a. What does the file command do?
- b. What type of data within files may confuse the
file command?
- c. Why might you use the file command?
- 54. Filenames and Filename Generation
- a. List five de facto standard filename
extensions.
- b. Why would you not want to use the ">" character in
a filename?
- c. What are some of the files matched by the filename
notation "?ite"?
- d. Why are you unable to use the "/" character within a
filename?
- e. How do you perform filename completion using the
ksh?
- f. How do you perform filename completion using the
csh?
- 55. find
- a. What does the find command do?
- b. Write the command to display all the files in your
HOME directory and all subdirectories.
- c. Write the command to remove all files which have not
been modified in 30 days, starting at the current directory.
- 56. finger
- a. What default information is displayed by the
finger command?
- b. What information is placed in the .project file?
- 57. fmt
- a. What function does the fmt command
perform?
- b. Write the command to format file1.
- c. Write the command to format the next paragraph inside
vi.
- 58. fold
- a. What does the fold command do?
- b. Describe some uses of the fold command.
- 59. getopts
- a. What is the purpose of the getopts
command?
- b. What are valid options for getopts -x:?
- c. If an argument is required after an option, where is
the argument stored?
- 60. grep
- a. What does the grep command do?
- b. What does the name "grep" mean?
- c. Write the command to locate all lines beginning with
"r" in the /etc/passwd file.
- 61. groups
- a. What does the groups command do?
- b. Explain the difference between your primary group and
secondary groups.
- 62. hash
- a. What is the purpose of the hash command?
- b. Can the hashing function be automatic; if so how?
- 63. head
- a. What is the function of the head command?
- b. Why might you want to use it?
- c. What does the command head +25 afile do?
- 64. history
- a. What specific file does the history command
display?
- b. How do you control the number of commands stored in
the history file for the ksh?
- c. How do your change the history character to a "." from
"!" in the csh?
- 65. hostname
- a. What does the hostname command do?
- b. What are some uses of the hostname
command?
- 66. id
- a. What information is displayed by the id
command?
- 67. Input/Output and Redirection
- a. What are the three standard types of I/O?
- b. Write the command to force the standard error onto the
standard output, for ksh and csh.
- c. How do you assure input is read from your keyboard by
the ksh's read command?
- d. Write the command to redirect the standard output to
file $X.
- 68. jobs
- a. Which shells support the jobs command?
- b. What is the purpose of the jobs command?
- 69. join
- a. What is the function of the join command?
- b. Write the command to join file1 and file2 on key
column 3.
- 70. kill
- a. What does the kill command do?
- b. What command is often used to provide PID information
so you can use the kill command?
- c. Why might you use the kill command?
- 71. ksh/csh/sh
- a. What two major functions does the Korn shell
provide?
- b. List 7 enhancments the ksh provides that the
sh does not.
- c. Which option automatically exports variables when they
are assigned a value?
- d. Which option might you use to debug a shell
script?
- e. What character would you use to separate three
commands on the same line?
- f. What character starts a comment in a shell
script?
- g. Which directory does the ~jim notation reference?
- h. What is the output of the echo 'My shell is
$SHELL' command?
- i. How do you enter "In-line Editing mode" (assume you
have EDITOR=vi)?
- j. Explain the difference between the . myscript
and myscript commands.
- 72. leave
- a. What function does the leave command
perform?
- b. When might you use it?
- 73. let
- a. What is an alternate syntax format to the let
command?
- b. Write the command to display the result of 1024 times
100, for the ksh and the csh.
- c. Which command does the let command
replace?
- 74. line
- a. What does the line command do?
- 75. listusers
- a. What information is displayed by the listusers
command?
- 76. ln
- a. What is the purpose of the ln command?
- b. Write the command to link file to filex.
- 77. login
- a. Why does the login command exist?
- 78. logname
- a. What does the logname command do?
- 79. lp
- a. What is the function of the lp command?
- b. How do you suppress the request information
message?
- c. Write the command to print the /etc/group file to the
lzr printer.
- 80. lpq
- a. Why might you use the lpq command?
- b. Write the command to display information about the
imagen printer.
- 81. lpr
- a. What does the lpr command do?
- b. Write the command to print file1 to the hplj
printer.
- 82. lprm
- a. What is the purpose of the lprm command?
- b. Write the command to remove print job 1362.
- 83. lpstat
- a. What information does the lpstat command
provide?
- b. Write the command to display all information about the
spooler.
- 84. ls
- a. What function does the ls command serve?
- b. Write the command to display all files in all
subdirectories.
- c. Write the command to display nonprintable
characters.
- d. Explain each position of the file modes.
- e. Write the command to allow other users to execute a
program as though they owned the program.
- 85. machid
- a. What is the function of the machid
commands?
- b. Why might you use these commands?
- 86. mail/mailx
- a. What is the purpose of the mail/mailx
command?
- b. What is the format of the mailx command to send
mail to a user?
- c. What is the format for reading mail from your mbox
file?
- d. How do you edit a message you are sending?
- e. When reading mail how do you display the next page of
header lines?
- f. When reading mail how do you delete messages 20
through 34?
- g. Write the internal command to send message 5 to the dp
printer.
- 87. man
- a. What does the man command do?
- b. Type the command to display information about the
vi command.
- c. On BSD what command searches man headers for matching
words?
- 88. mesg
- a. What is the purpose of the mesg command?
- b. Write the command to prevent messages?
- 89. mkdir
- a. Explain why or why not the command mkdir src/cmd
src works.
- b. What does the SV -m option do?
- c. On SV how can you make the command in a. work?
- 90. more/page
- a. What is the purpose of the more command?
- b. When might you want to use more?
- c. Write the internal command to find the first
occurrence of "string" in the current text of more input.
- d. How do you scroll down the input?
- 91. mv
- a. What are three uses of the mv command?
- b. What two commands does the mv command use to
perform its job?
- c. Write the command to rename ../file1 to
src/myprog.c.
- 92. newgrp
- a. Describe the function of the newgrp
command.
- b. Why would you use the newgrp command?
- 93. news
- a. What does the news command do?
- b. How do you force all news items to be displayed?
- 94. nice
- a. What does the nice command change?
- b. What are some uses of the nice command?
- 95. nl
- a. Describe the function of the nl command.
- b. Write the command to number lines in increments of 10
and zero fill five spaces.
- 96. nohup
- a. What is the purpose of the nohup command?
- b. Where is the output of the nohup command written?
- c. Can you redirect the output to a file?
- 97. od
- a. What formats of output data does the od command
support?
- b. What does the -c option do?
- c. How do you display data in hexidecimal format?
- 98. pack/unpack
- a. What does the pack command do?
- b. How do you reverse the effects of the pack
command?
- c. Do you have to specify the .z extension when unpacking
a file?
- 99. Parameters/Variables/Arrays
- a. What is the shell "environment"?
- b. How can you set positional parameters from within a
shell?
- c. Which variable contains the return status of the last
command?
- d. Write the command for assigning "Subscript 100" to the
100th position of the array ex_array.
- e. What is the syntax for referencing positional
parameter 23?
- f. Name one situation where using an array would be
better than using variables.
- 100. passwd
- a. Explain password aging.
- b. What are the requirements of SV passwords?
- c. What are two reasons for using the passwd
command?
- 101. paste
- a. List the functions of the paste command.
- b. Write the command to display the standard input as 5
columns.
- 102. pcat
- a. When do you use the pcat command?
- b. What extension must the file have to use
pcat?
- 103. pg
- a. List some of the features of the pg
command?
- b. What does the -n option do?
- c. Write the command to reset the pg prompt to
"Press CR to continue."
- d. How do you search for a string from the command
line?
- e. What types of commands are supported by
pg?
- f. How do you search backward from the pg
prompt?
- g. Write the command to skip forward 3 files.
- 104. popd
- a. Explain what the popd command does.
- b. Which command must be used before popd can be
used?
- 105. pr
- a. What is the function of the pr command?
- b. Write the command to convert input tabs to 4
spaces.
- c. How do you double space the output using
pr?
- d. Write the command to change the header to "My test pr
command."
- e. Generate a listing of files in 3-column output using
just pr.
- 106. print
- a. Explain the two different print commands.
- b. Write two versions of print that do not print a
new-line.
- c. How do you save the output of the print command to the
history file?
- 107. printenv
- a. What is the purpose of the printenv
command?
- b. When might you use the printenv command?
- 108. Programming Constructs - Shell Programming
- a. List the steps you follow to create a shell
script.
- b. Change the lg shell script to display the
information field of the /etc/passwd file. The information field is field
5.
- c. List the three types of looping conventions supported
by the shells.
- d. Why use the case statement instead of the
if statement?
- e. What are the benefits of using functions?
- 109. ps
- a. What is the function of the ps command?
- b. If the output is greater than 132 columns, what option
do you use to display it correctly?
- c. How do display information about all processes on SV
and or BSD?
- 110. pushd
- a. Explain the directory stack.
- b. Why do you use the directory stack?
- 111. pwd
- a. What does the pwd command do?
- b. Why use the pwd command?
- 112. read/readonly/set $<
- a. What does the read command do with the input it
reads?
- b. What does the readonly command do that
read does not?
- c. If you have a command read X Y and your input
is "INPUT HERE," what is the value of Y?
- 113. Regular Expressions (REs)
- a. Explain a regular expression.
- b. Why are they so valuable?
- c. Write the regular expression to match multiple
occurrences of the same character.
- d. How do you reference regular expressions that have
been grouped?
- 114. rm
- a. What function does the rm command perform?
- b. Why might you use the rm command?
- c. How do you remove directories with the rm
command?
- 115. rmdir
- a. What condition must the directory be in before
rmdir will work?
- b. Explain the -p option on SV rmdir.
- 116. script
- a. What is the purpose of the script command?
- b. What file does the script file create by
default?
- 117. sed
- a. What is sed?
- b. Explain how it basically works.
- c. Write the command to subsitute all occurrences of
"system" with "computer."
- d. Which commands allow you to insert text?
- e. Write a sed command to display the first 100
lines of a file.
- 118. set/unset
- a. What functions does the ksh and sh set
command provide?
- b. What does the csh set command do?
- c. How do you display the local environment using
set (ksh and sh)?
- d. Write the csh command to set TERM to
vt100.
- 119. setenv/unsetenv
- a. What does the setenv command do with
variables?
- b. Can a child process change the environment of a parent
process?
- c. How could you pass a variable's value to a parent
shell?
- 120. shift
- a. What does the shift command do?
- b. Write the command to shift all but one parameters
(hint: use the eval command).
- 121. sleep
- a. Explain the sleep command.
- 122. sort
- a. What type of files does the sort command
sort?
- b. Write the command to sort on field 5.
- c. How do you sort numbers?
- d. Can sort reverse the order of the sort?
- e. How do you remove duplicate adjacent lines?
- 123. spell
- a. How can you use your own list of correctly spelled
words?
- b. What are the shortcomings of the spell
command?
- 124. split
- a. Explain how the split command functions.
- b. Write the command to split myfile into 10 line files
whose names begin with mysplit.
- 125. stop
- a. What does the stop command do?
- b. What state must a process be in before you can use the
stop command on the process?
- c. How does the ksh implement the stop
command?
- 126. stty
- a. What is the purpose of the stty command?
- b. Write the SV and BSD command to display all
settings.
- c. Write the command to change your erase key to Ctrl-B
and your kill key to Ctrl-K.
- d. What happens if you type the stty -echo
command?
- e. What happens if you disable isig (stty -isig)?
- f. What is the default EOF character for stty
(UNIX)?
- 127. su
- a. What is the function of the su command?
- b. Explain what happens if you don't use the -
option.
- c. Why might you use the su command?
- 128. sum
- a. List some uses of the sum command.
- 129. suspend
- a. What is the purpose of the suspend
command?
- b. What is the format of the suspend command?
- c. How do you restart a suspended job?
- 130. tabs
- a. Explain what the tabs command does.
- b. What is meant by "canned" tab formats?
- c. Why must tabs know your terminal type?
- 131. tail
- a. What is the purpose of the tail command?
- b. What does the -f option cause tail to do?
- c. Write the command to skip the first 25 lines of
myfile.
- 132. talk
- a. Describe the talk command.
- b. Write the command to talk to john at utvax.
- 133. tar
- a. What is the function of the tar command?
- b. Why might you use the tar command?
- c. Write the command to tar your current directory to
/dev/rmt/0m.
- 134. tee
- a. What is the function of the tee command?
- b. What does the -a option do?
- c. What is the name of the output files from
tee?
- 135. test
- a. Explain the function of the test command.
- b. Write the command to compare two numbers, $X and
$Y.
- c. Write the command to find out if a file is readable
and writable.
- 136. time/timex
- a. What is the function of the timex command?
- 137. time/times
- a. What is the purpose of the times command?
- b. Explain how the time command functions.
- 138. touch
- a. What is the function of the touch command?
- b. What is the difference between the SV and BSD
touch commands?
- c. Write the command (SV) to create a file with the date
of Nov 11, 1989 at 12:00 noon.
- 139. tput
- a. What does the tput command do?
- b. Write the command to clear your terminal screen.
- c. Write the command to move your cursor to position 10
20 on your screen.
- 140. tr
- a. What is the function of the tr command?
- b. Write the command to translate all numbers to
dashes.
- 141. trap/onintr
- a. Explain what the trap command does.
- b. Write the trap command to rm all files in /tmp
with names ending in .$$ if you press the Delete key (Signal 2).
- 142. true
- a. What is the function of the true command?
- b. What is the return code of the true
command?
- 143. tset
- a. Explain what the tset command does.
- b. Write the command using tset to set your erase
key to Ctrl-H and set your terminal type to vt100 if you're on a tty with a
baud rate higher than or equal to 9600.
- c. What file might you place the tset command in
for regular use?
- 144. tty
- a. What information does the tty command
display?
- b. When might you use the tty command?
- 145. typeset
- a. What does the typeset command allow you to do
with shell variables?
- b. Write the command to display a variable with 5
positions and zero filled.
- c. What does the -l option cause typeset to
do?
- 146. ulimit/limit
- a. What does ulimit limit?
- b. What does the limit command limit?
- c. How can you as a user reset your ulimit to a higher
value?
- 147. umask
- a. Explain the function of the umask command.
- b. What does the umask 023 command force for
permissions on newly created files?
- 148. uname
- a. What information is displayed by the uname
command?
- 149. uniq
- a. What function is performed by the uniq
command?
- b. How do you display only uniq lines?
- c. Write the command to compare only columns 20 and
higher.
- 150. users
- a. What information is displayed by the users
command?
- b. Why would you use the users command?
- 151. vi/view
- a. What is vi?
- b. What must you do before using vi?
- c. How do you start vi and have it position you at
a certain string in the file?
- d. What are the six operators used by vi?
- e. How do you recover a file using vi?
- f. What are the modes within vi?
- g. Explain what a register is in vi.
- h. Describe how to copy text between two buffers.
- i. How do you move to the top line of the buffer?
- j. Write the command to filter the entire buffer through
the sort -u command.
- k. How do you mark an address and how do you reference
the marked address?
- l. Create a string macro to write the current file to
disk and edit the next file in the argument list.
- 152. wait
- a. What function does the wait command serve?
- b. When do you use it?
- 153. wall
- a. What does the wall command do?
- b. When is it often used?
- c. Who usually uses the wall command?
- 154. wc
- a. What units are displayed by the wc
command?
- b. Write the command to count the number of characters in
all files beginning with a "f."
- 155. whatis
- a. Why would you use the whatis command?
- b. Is the information displayed always decisive and
helpful?
- 156. whence/type
- a. Explain the function of the whence
command.
- b. Why do we need the whence command?
- 157. whereis
- a. What information does the whereis command
display?
- b. How do you force whereis to only search for man
page entries?
- c. Can you change the directories whereis
searches? If so, how?
- 158. which
- a. What is the function of the which command?
- b. What does the which command display if the
command is not located?
- 159. who
- a. What is the function of the who command?
- b. How many options does the BSD version support?
- c. What does the -u option do?
- d. How can you display the number of users currently on
the system?
- 160. whoami
- a. What information does the whoami command
display?
- 161. write
- a. What does the write command do?
- b. How do you terminate the write command to send
the message?