Introduction to Unix (CA263) Unix/Linux Utilities

1
Introduction to Unix (CA263) Unix/Linux
Utilities

• By
• Tariq Ibn Aziz

2
Objectives

• Check File Type
• Unix utilities more, less, head, tail command
• Check Spelling
• Splitting a File
• comm and diff command
• Regular Expression rules
• grep and egrep Printing Files
• PostScript and PDF Files
• Encrypting and Decrypting a File
• mpage versus enscript

3
Check File Type

• Unixgt file .login
• .login assembler program text
• (Page 28)

4
more or less

• Less is an improved version of more command.
• You can say that more is less than less, and less
  is more than more.
• (Page 62)

5
head or tail

• head view lines at the beginning of a file, by
  default, it display 10 line from top
• tail view lines at the end of a file, by
  default, it display 10 line from bottom
• (Page 63)

6
Check Spelling

• Unixgt spell info.txt
• Username
• dis
• For interactive spell checking use ispell. For
  more information see man ispell
• (page 64)

7
Split a File

• Unixgt vi data.txt
• Username
• Tariq
• Naif
• Musa
• Manea
• Hassan
• Monim
• To split data file into files with 2 line each.
• Unixgt split -2 data.txt stuff
• unixgt ls stuff
• Stuffaa stuffab stuffac stuffad

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8
comm

• comm is very handy command.
• comm file1 file2 will report three column report.
• Unique lines in f.txt, unique lines in g.txt, and
  duplicate lines

• unixgt comm f.txt g.txt
• jay
• pat
• kit
• sam
• joe

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9
diff

• diff file1 file2
• lt sign indicates file1
• gt sign indicates file2
• 1d0 is number-letter-number
• 1 indicates a line in first file
• a, c, or d indicates an ed command, a append, c
  change, d mean delete.
• 0 third char indicates a line in second file.
• lt pointing first file
• gt pointing second file

• unixgt diff f.txt g.txt
• 1d0
• lt jay
• 2a2
• gt kit

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Regular Expression rules

• . Matches any single character For example .at
  matches aat, bat, cat,
• matches one character between brackets
• "-" indicates range. E.g. a-z
• matches zero or more instance, For example ba
  macthes b, ba, baa,
• \ treat the next character literally, for example
  \ matches "
• matches the start of the line, So cat matches
  every line that start with cat
• matches the end of line. So cat matches every
  line that end with cat e.g. aristocat

Page 69, 70
11
grep (global regular expression print)

• unixgtcat f.txt
• jay
• pat
• sam
• joe
• unixgtcat g.txt
• pat
• kit
• sam
• joe

• unixgt grep pat f.txt g.txt
• f.txtpat
• g.txtpat
• unixgt grep n pat f.txt g.txt
• f.txt2pat
• g.txt1pat

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grep (global regular expression print)

• unixgtcat f.txt
• jay
• pat
• sam
• joe
• unixgtcat g.txt
• pat
• kit
• sam
• joe

• Search all rows start with "p"
• unixgt grep n 'p' f.txt
• 2pat
• Search all rows start with "k or j"
• unixgt grep n 'kj' g.txt
• g.txt2kit
• g.txt4joe
• Search all rows with one or more "a"
• unixgt grep n 'a' g.txt
• g.txt1pat
• g.txt3sam

Page 70
13
egrep (extended global regular expression print)

• Some of the extended set is as follow
• matches one or more of its preceding
  characters, e.g. abc2 will match abc2, abc22,
  abc222,
• ? matches zero or one character that precedes it,
  e.g. abc? Matches with ab and abc
• signifies an alternative or disjunction. e.g.
  ab means a or b
• unixgt egrep uuww /usr/dict/words
• Continuum
• Hollowware
• vacuum

Page 72
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egrep (extended global regular expression print)

• Search for line that have z or v in info.txt
• unixgt egrep '(zv)' info.txt
• Name David I. Schwartz
• Favorite Color blue

Page 72
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Printing Files

• The common print command is lp, which stands for
  line printer, lp work with spooling a file.
• unixgt lp info.txt
• request if is jaded-2 (1 file)
• Request id has the form printer-job number .
• jaded is a printer.
• My job is the 2nd print job.
• unixgt echo PRINTER
• jaded

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Find other printers

• unixgt printers
• Printer Type Location Owner/User
• astro HP2420 ROOM 271

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Print to Destination

• unixgt lp d astro a.txt
• Some version of unix use the BSD print command
• unixgt lpr P astro b.txt

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Printing Status

• lpq and lpstat have different output format
• unixgt lpstat
• Jaded-2 dis 163 Nov 22 1833
• unixgt lpq
• Jaded_at_blather 0 jobs

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Cancel a Print Job

• lpq and lpstat have different output format
• unixgt lpstat
• Jaded-2 dis 163 Nov 22 1833
• unixgt cancel jaded-2
• request "jaded-2" cancelled

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PostScript

• PostScript (PS) is a text-based language that can
  describe graphical images and text.
• You should be able to print a PS document
  anywhere.
• PS document can be generated from a text file
  with genscript.
• unixgt genscript info.txt gt info.ps
• unixgt

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View PostScript Document

• Use ghostview or gs to view PS version of info.ps
• unixgt gs info.ps
• GSgt quit
• unixgt

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Print PostScript Document

• unixgt lp d jaded info.ps
• unixgt
• You can do some conversions at the Unix command
  line.
• pdf2ps convert PDF file to PS format
• ps2pdf convert PS file to PDF format
• ps2ascii convert PS file to ACSII format
• PDF (portable Document Format) need acroread or
  xpdf utilities to display the PDF file

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Viewing and Printing PDF Files

• unixgt acroread info.pdf
• unixgt
• You can do some conversions at the Unix command
  line.
• pdf2ps convert PDF file to PS format
• ps2pdf convert PS file to PDF format
• ps2ascii convert PS file to ACSII format
• PDF (portable Document Format) need acroread or
  xpdf utilities to display the PDF file

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Encrypting a File

• unixgt cat info.txt
• Trans fat is evil.
• unixgt crypt lt info.txt gt info.enc
• Enter Key (Enter 12345)
• Try more info.enc, unix wil prompt you to view a
  binary file.

25
Decrypting a File

• unixgt crypt lt info.enc gt info.dec
• Enter Key (Enter 12345)
• Try more info.dec, unix wil prompt you to view a
  binary file.
• unixgt more info.dec
• Trans fat is evil.

26
mpage versus enscript

• mpage to print multiple page on one sheet, you
  can print 1, 2, 4 or 8 pages on one side of a
  sheet of paper.
• If mpage is not available then use enscript

27
Print a File using enscript

• unixgt enscript r B columns4 f Helvetica10 p
  movies.ps movies.txt
• This command will create movies.ps from
  movies.txt
• The enscript command do the following
• print PS file (-p info.txt)
• in landscape (-r)
• with no header (-B)
• four column (--columns4)
• in a plain font (-f Helvetica10)