Prsentation PowerPoint

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More UNIX Utilities for Shell programming
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at-at, batch--execute commands at a later time
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awk--pattern scanning and processing language
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banner--make posters
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basename--with a directory name delivers portions
of the pathname
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bc--processes precision arithmetic
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bdiffcompares two big files

• bdiff compares two files that are too large for
  diff.

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caldisplays a calendar
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catconcatenates and displays files
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chmodchange the permissions mode of a file
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chownchanges owner of a file
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clear, clears the terminal screen
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cmpcompares two files
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compresscompress, uncompress, zcat compress,
uncompress files, or display expanded files
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cp copies files
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cpio copy file archives in and out
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cronthe clock daemon

• cron executes commands at specified dates and
  times. Regularly scheduled jobs can be specified
  in the /etc/crontab file. (Must have superuser
  privileges)

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cryptencode or decode a file

• crypt encrypts and decrypts the contents of a
  file. The password is a key that selects a type
  of transformation

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cutremoves selected fields or characters from
each line of a file
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datedisplays the date and time or sets the date
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diffcompares two files for differences diff
-biw-c -Cn
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dusummarizes disk usage
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echoechoes arguments
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egrepsearches a file for a pattern using full
regular expressions
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exprevaluates arguments as an expression
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fgrepsearch a file for a character string
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filedetermines the type of a file by looking at
its contents
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findfinds files
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fingerdisplays information about local and
remote users

• By default, the finger command displays
  information about each logged in user, including
  login name, full name, terminal line (prepended
  with a if write permission is denied), idle
  time, login time, and location if known

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fmtsimple text formatters
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foldfolds long lines

• Fold the contents of the specified filenames, or
  the standard input if no files are specified,
  breaking the lines to have maximum width. The
  default for width is 80. Width should be a
  multiple of 8 if tabs are present, or the tabs
  should be expanded

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ftpfile transfer program
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getop(s)parses command line options

• The getopts command supersede getop. getops is
  used to break up options in command lines for
  easy parsing by shell procedures and to check for
  legal options.

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grepsearches a file or a program
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groupsprints group membership of user

• The command groups prints on standard output the
  groups to which you or the optionally specified
  user belong.

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idprints the username, user ID, group name and
group ID

• id displays your user ID,user name, group ID, and
  group name. If your real ID and your effective
  IDs do not match, both are printed.

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jshthe standard, job control shell

• The command jsh in an interface to the standard
  Bourne shell which provides all of the
  functionality of the Bourne shell and enables job
  control.

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linereads one line

• line copies one line (up to a new line) from the
  standard input and writes it on the standard
  output. It returns an exit code of one on EOF and
  always prints at least a new line. It is often
  used within shell files to read from the users
  terminal.

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lognamegets the name of the user running the
process
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lp(ATT)sends output to a printer
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lpr(UCB)sends output to a printer
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lpsat(ATT)print information about the status of
the LP print service
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lpq(UCB)print information about the status of
the printer
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ls lists a contents of directory
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mailmail, rmailread mail or send mail to users

• A recipient is usually a username recognized by
  login. When recipients are named, mail assumes a
  message is being sent. It reads from the standard
  input up to an end-of-file(Ctrl-D), or if reading
  from a terminal, until it reads a line consisting
  of just a period. When either of those indicators
  is received, mail adds the letter to the mailfile
  for each recipient.

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mailxinteractive message processing system

• The mail utilities listed above provide an
  interactive interface for sending, receiving, and
  manipulating mail messages. Basic networking
  utilities must be installed for some of the
  features to work. Incoming mail is stored in a
  file called mailbox, and after it is read, it
  sends to a file called mbox

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makemaintains, updates, and regenerates groups
of related program and files

• make updates file according to commands listed in
  a description file, and if the target file is
  newer than the dependency file of the same name,
  make will update the target file.

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mesgpermits or denies messages resulting from
the write command

• mesg without argument n forbids messages via
  write by revoking no user write permission on the
  users terminal. mesg with argument y reinstates
  permission. All by itself, mesg reports the
  current state without changing it.

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mkdircreates a directory
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morebrowse or page through a text file

• more is a filter that displays the contents of a
  text file on the terminal, one screenful at a
  time. It normally pauses after each screenful,
  and prints More at the bottom of the screen.

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mvmove or rename files
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nawkpattern scanning and processing language

• nawk scans each input filename for lines that
  match any of a set of patterns. The command
  string must be enclosed in single quotes() to
  protect it from the shell. awk programs consists
  of a set of pattern/action statements used to
  filter specific information from a file, pipe, or
  stdin.

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newgrplog in to a new group

• newgrp logs a user into a new group by changing a
  users real and effective group ID. The user
  remains logged in and the current directory in
  unchanged. The execution of newgrp always
  replaces the current shell with a new shell,
  even if the command terminates with an error
  (unknown group)

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newsprints mew items

• news is used to keep the user informed of current
  events. By convention, these events are described
  by files in the directory /var/news. When invoked
  without arguments, news prints the contents of
  all current files in /var/news, most recent
  first, with each preceded by an appropriate header

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niceruns a command at low priority

• /usr/bin/nice executes a command with a lower CPU
  scheduling. The invoking process (generally the
  users shell) must be the time-sharing scheduling
  class. The command is executed in the
  time-sharing class. An increment of 10 is the
  default. The increment must be a range between 1
  and 19, unless you are the superuser. Also a csh
  built-in.

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nohupmakes commands immune to hang-ups and quits
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odoctal dump

• od displays filename in one or more formats, as
  selected by the first argument. If the first
  argument is missing, -o is default e.g., the
  file can be displayed in bytes octal, ASCII,
  decimal, hex, etc.

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packpack, cat, unpack--compresses and expands
files

• pack compresses files. Wherever possible (and
  useful), each input file name is replaced by a
  packed file name.z with the same access modes,
  access and modified dates, and owner as those of
  name. Typically, text files are reduced to 60-70
  of their original size. pcat does for packed file
  what cat does for ordinary files, except that
  pcat cannot be used as a filter. The specified
  files are unpacked and written to the standard
  output. Thus to view a packed file named name.z
  use pcat name.z or just pcat name. unpack
  expands files created by pack.

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passwdchanges the login password and password
attributes

• The passwd command changes the password or lists
  password attributes associated with the users
  login name. Additionally, privileged users may
  use passwd to install or change passwords and
  attributes associated with any login name.

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pastemerges same line of several files or
subsequent lines of one file
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pcat(see pack)
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pgdisplays files a page at a time

• The pg command is a filter that allows you to
  page through one sreenful at a time on a
  terminal. If no filename is specified or it
  encounters the file name -, pg reads from
  standard input. Each screenful is followed by a
  prompt. If the user types a RETURN, another page
  is displayed. It allows you to back up and review
  something that has already passed.

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prprints file
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psreports process status
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pwddisplays the present working directory
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rcpremote file copy
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rshstarts a remote shell
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ruptimeshows the host status of local machines

• ruptime gives a status line like uptime for each
  machine on the local network these are formed
  from packets broadcast by each host on the
  network once a minute. Machines for which no
  status has been received for five minutes are
  shown as being down. Normally, the listing is
  sorted by host name, but this order can be
  changed by specifying one of ruptimes options

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rwhowho is logged in on local machine

• The rwho command produces output similar to who,
  but for all machines on your network. However, it
  does not work through gateways and host must have
  the directory /var/spool/rwho as well as the rwho
  daemon running. If no report has been received
  from a machine for five minutes, rwho assumes the
  machine is down, and does not report users last
  known to be logged into that machines. If a user
  has no typed to the system for a minute or more,
  rwho reports this idle time. If a user has not
  typed to the system for an hour or more, the user
  is omitted from the output of rwho, unless the a
  flag is given

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scriptcreates a typescript of a terminal session
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sedstream editor
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sizeprints section sizes in bytes of object files

• The size command produces segment or section size
  information in bytes for each loaded section in
  ELF or COFF objects files. size prints out the
  size of the next, data, and bss (uninitialized
  data) segments (or section) and their total

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sleepsuspends execution for some number of
seconds
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sortsort and/or merge file
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spellfinds spelling errors

• spell collects word from the named filenames and
  looks them up in a spelling list. Words that
  neither occur among nor are derivable from words
  in the spelling list are printed on the standard
  output. If no filenames are named, words are
  collected from the standard input

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splitsplits a file into pieces
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stringsfinds any printable string in an object
or binary file
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sttysets the options for a terminal
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subecome super-user or another user

• su allows one to become another user without
  logging off. The default username is root
  (superuser). To use su, the appropriate password
  must be supplied (unless the invoker is already
  root). If the password is correct, su creates a
  new shell process that has the real and effective
  user ID, group Ids, and supplementary group list
  set to those of the specified username. The new
  shell is specified, sh (Bourne shell) is used. To
  return to normal user ID privileges, type Ctrl-D
  to exit the new shell. The - option specifies a
  complete login.

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sumcalculates a checksum for a file
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syncupdates the super block and sends changes
blocks to disk
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tabssets tab stops on a terminal
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taildisplays the tail end of a file
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talkallows you to talk to another user
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tarstores and retrieves files from an archive
file, normally a tape device
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teereplicates file standard output
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telnetcommunicates with a remote host
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testevaluates an expression
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timedisplays a summary of time used by this
shell and its children
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touchupdates access time and/or modification
time of a file
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tputinitializes a terminal or queries the term
info database
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trtranslates characters
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trueprovide successful exit status

• true does nothing, successfully, meaning that it
  always returns a zero exit status, indicating
  success. Used in Bourne and Korn shell programs
  as a command to start an infinite loop
• while true
• do
• command
• done

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tsorttopological sort

• The tsort command produces, on the standard
  output, a totally ordered list of items
  consistent with a partial ordering of items
  mentioned in the input filename. If no filename
  is specified, the standard input is understood.
  The input consists of pairs of items (nonempty
  strings) separated by blanks. Pairs of different
  items indicate ordering. Pairs of identical items
  indicate presence, but not ordering

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ttygets the name of the terminal

• tty prints the path name of users terminal

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umasksets file-creation mode mask for permissions
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unameprints name of current machine
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uncompressrestores files to their original state
after they have been compressed using the
compress command
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uniqreports on duplicate lines in a file
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unitsconverts quantities expressed in standard
scales to other scales

• units converts quantities expressed in various
  standard scales to their equivalents in other
  scales. It works interactively in this fashion
• You haveinch
• You wantcm
• 2.540000e00
• /3.937008e-01

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unpackexpands files created by pack

• unpack expands files created by pack. For each
  filename specified in the command, a search is
  made for a file called name.z (or just name, if
  name ends in .z). If this file appears to be
  packed file, it is replaced by its expanded
  version. The new file has the .z suffix stripped
  from its name, and has the same access modes,
  access and modification dates, and owner as those
  of the packed file

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uucpcopy files to another system, UNIX-to-UNIX
system copy
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uuencodeuuencode, uudecodeencode a binary file
into ASCII text in order to send it through
e-mail, or convert it back into its original form
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wccounts lines, words, and characters
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whatextracts SCCS version information from a
file by printing information found after the _at_()
pattern

• What searches each filename for the occurrence of
  the pattern, _at_(), that the SCCS get command
  substitutes for the Z keyword, and prints what
  follows up to a gt, new line, \, or null character

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which(UCB)locates a command and displays its
pathname or alias

• which takes a list of names and looks for the
  files that would be executed had the names been
  given as commands. Each argument is expanded if
  it is aliased, and searched for along the users
  path. Both alias and path are taken from the
  users .cshrc file. Only .cshrc is used

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whereis(UCB)locates the binary, source, and
manual page file for a command
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whodisplays who is logged on the system
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writewrites a message to another user

• Writes copies to lines from your terminal to
  anothers terminal

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xargsconstructs an argument list(s) and executes
a command
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zcatuncompress a compressed file to standard
output. Same as uncopmress -c
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References

• UNIX SHELLS BY EXAMPLE BY ELLIE QUIGLEY
• UNIX FOR PROGRAMMERS AND USERS BY G. GLASS AND K
  ABLES
• UNIX SHELL PROGRAMMING BY S. KOCHAN AND P. WOOD