Shell Programming Details (iii)

String test:

= =: Test for equality, equality is true, not equal to False

! =: Tests are not equal, unequal to true, equal to False

>

<

-N String: Tests whether the specified string is empty, empty is true, not empty is false

-S string: Tests whether the specified string is not empty, is not empty, and empty is false

BC Command usage

For example: echo "SCALE=2;111/22;" | BC reserved two-bit accuracy

Loop control

For

While

Until

for variable in list; Do

Loop body

Done

Generating a list of integers

1. {1..100}

2, ' SEQ [number of start] [step] End number

For example: SEQ 1 2 10 generates cardinality from 1 to 10

Script instance: Generate 10 random numbers and find the maximum and minimum values

#!/usr/bin/ksh

Declare-i max=0

Declare-i min=0

For num in {1..10}

Do

Myrandom= $RANDOM

If [$num-eq 1]; Then

min= $myRandom

Fi

If [$num-lt 10]

Then

Echo-n "$myRandom,"

Else

echo "$myRandom"

Fi

[[$myRandom-gt $max]] && max= $myRandom

[[$myRandom-lt $min]] && min= $myRandom

Done

echo "Max= $max"

echo "Min= $min"

Case statement:

Case variable in

value1)

statement;;

Values

statement;;

*)

statement;;

Esac

This article is from the "Forget the Past" blog, please be sure to keep this source http://xujingbo.blog.51cto.com/4633099/1828219

Shell Programming Details (iii)