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Problem with sed (search/replace)

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# 1  
Old 08-26-2008
Problem with sed (search/replace)
Hi,

In a file FILE, the following lines appear :

Code:
WORD 8 8 8
ANOTHERWORD blabla
...

Directly in the prompt, if I type

Code:
$sed '/WORD/s/8/10/g' FILE

it replace the 8's by 10's in file :

Code:
$cat FILE
WORD 10 10 10
ANOTHERWORD blabla
...

This is exactly what I want to do. Then, if instead in the prompt, I define

Code:
$before=8
$increment=2

and if I type

Code:
$sed '/WORD/s/'$before'/'$[$before + $increment]'/g' FILE

It also work perfectly (8's replaced by 10's).

Now, if instead in a script, the following line appear in a while loop

Code:
max=12
increment=2
before=10
while [ $before -le $max ]
do
   sed -i_temp '/WORD/s/'$before'/'$[$before + $increment]'/g'  FILE
   before=$[$before + $increment]
done

And if I run the script, it doesn't work! It replace "8 8 8" by "10" instead of "10 10 10"

What is my problem?

Thanks a lot for your help,

Tipi
# 2  
Old 08-26-2008
I forgot to say that max, before and increment are in fact arrays. So, when I call, $max, $increment, or $before, I call the element [0] of these arrays.

Maybe this can be the source of the problem? Instead of
max=12
increment=2
before=10
in the last post, you should read
max=( 12 12 12 )
increment=( 2 2 2 )
before=( 10 10 10 )

everything else stay the same.
# 3  
Old 08-26-2008
This doesn't work for me :
Quote:
$sed '/WORD/s/'$before'/'$[$before + $increment]'/g' FILE
If using variables in sed then use double quotes. Try this :
Quote:
sed "/WORD/s/$before/$[$before + $increment]/g" FILE
# 4  
Old 08-26-2008
Replace single quotes by double quotes in your sed command (variables will be expanded) and use (( )) for calculations
Code:
max=12
increment=2
before=10
while [ $before -le $max ]
do
   sed -i_temp "/WORD/s/$before/$((before + increment))/g"  FILE
   (( before = $before + $increment ))
done

Jean-Pierre.
Last edited by aigles; 08-26-2008 at 05:49 PM.. Reason: Quoting corrections
# 5  
Old 08-26-2008
My script is really huge so, right after the sed line, I added

echo "before+increment=$[$before+$increment]" >> REPORTFILE
echo "Wrote : `grep WORD FILE`" >> REPORTFILE

When I look in the REPORTFILE file, I can read :

before+increment=12
Wrote : WORD 12

So
WORD 10 10 10
really became
WORD 12

This is the same with single quote like in my fisrt post, or with double quoted sed :

sed -i_temp "/WORD/s/$before/$[$before + $increment]/g" FILE

Thanks a lot for your help,

Tipi
# 6  
Old 08-26-2008
Quote:
Originally Posted by aigles
Replace single quotes by double quotes in your sed command (variables will be expanded) and use (( )) for calculations
Code:
max=12
increment=2
before=10
while [ $before -le $max ]
do
   sed -i_temp "/WORD/s/'$before'/'$((before + increment))"/g'  FILE
   (( before = $before + $increment ))
done

Jean-Pierre.
Are the last " and ' to be interchanged? Because I have an open quote error...
# 7  
Old 08-26-2008
Run ur script using sh -x and check what is the sed command that is getting executed.
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