Unix Lecture 8

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Unix Lecture 8

• Hana Filip

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Hints for shell script writing HW 7 - quiz
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foreach

• foreach loop
• foreach var ( worddlist )
• command(s)
• end
• it loops through a range of values.
• it makes a variable take on each value in a
  specified set, one at a time, and performs some
  action

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while and foreach

• foreach var ( worddlist )
• command(s)
• end
• while ( expr )
• command(s)
• end

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while

• while loop
• while ( condition )
• command(s)
• end
• The while statement best illustrates how to set
  up a loop to test repeatedly for a matching
  condition
• The while loop tests a condition in a manner
  similar to the if statement
• As long as the condition is true, the command(s)
  repeat(s)

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while

• Adding integers from 1 to 10
• !/bin/csh
• set i1
• set sum0
• while (i lt 10)
• echo Adding i to the sum.
• set sumexpr sum i
• set iexpr i 1
• end
• echo The sum is sum.

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input from the keyboard

• set ans lt

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generating numbers

• jot

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generating numbers

• jot 3 1
• 1
• 2
• 3
• generates a series of numbers (3) beginning at 1.

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generating numbers

• jot 5 2
• 2
• 3
• 4
• 5
• 6
• generates a series of numbers (5) beginning at 2.

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generating numbers

• jot 10 20
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29

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generating numbers

• A primer on using 'jot' in UNIX
• http//www.macosxhints.com/article.php?story20011
  117235743849

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counter operator

• the increment operator means add one to a
  variable or make a variable's value one more
  than it was before.

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counter operator

• used in connection with awk program
• vi awklw
• ! /usr/bin/awk -f
• BEGIN nl 0 nw 0
• nl nw NF
• END print "Lines", nl, "words", nw
• chmod x awklw
• awklw machen.txt
• Lines 2538 words 21853