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simple expr

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  #1  
Old January 17th, 2005, 07:23 PM
izza_azhar izza_azhar is offline
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simple expr
if program such
x=0
for i in 1 2 3
do
x=' expr $x + 10 '
echo $i $x
done

the output should be:
1 10
2 20
3 30

but why i get output such:
1 expr $x + 10
2 expr $x + 10
3 expr $x + 10

it didn't do the calculating?
why?
i have to pass the variable to continue my assignment
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  #2  
Old January 18th, 2005, 05:48 AM
guggach guggach is offline
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you are using
x=' expr $x + 10 '
instead of
x=`expr $x + 10`
nota: no spaces and the single quote avoids the replacement
of $x
on *nix 'bc' is better then 'expr'
x=`echo 23456/22¦bc`
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  #3  
Old January 18th, 2005, 06:10 AM
zlutovsky zlutovsky is offline
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Quote:
Originally Posted by guggach
you are using
x=' expr $x + 10 '
instead of
x=`expr $x + 10`
nota: no spaces and the single quote avoids the replacement
of $x
on *nix 'bc' is better then 'expr'
x=`echo 23456/22¦bc`



Well, and in Korn shell you can simply write

let x=x+10

Regards
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  #4  
Old January 18th, 2005, 06:40 AM
guggach guggach is offline
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not sure this is correct
Quote:
let x=x+10

anyway, bourne, korn, c or bash ....
the probl is this guy does not know/respect the syntax.
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  #5  
Old January 18th, 2005, 08:02 AM
zlutovsky zlutovsky is offline
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Quote:
Originally Posted by guggach
not sure this is correct

anyway, bourne, korn, c or bash ....
the probl is this guy does not know/respect the syntax.



I am sure guggach, in Korn shell

let x=x+10

is correct. In bash, too. Try it.

Regards zlutovsky
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  #6  
Old January 18th, 2005, 12:23 PM
vgersh99 vgersh99 is offline
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Quote:
Originally Posted by zlutovsky
I am sure guggach, in Korn shell

let x=x+10

is correct. In bash, too. Try it.

Regards zlutovsky


Code:
#!/bin/ksh

typeset -i x=5

(( x+=10 ))

echo "x->[${x}]"
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  #7  
Old January 23rd, 2005, 09:51 PM
izza_azhar izza_azhar is offline
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thanks
thanks everybody for helping me!
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