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Old 03-22-2010, 04:06 AM   #1
quanba
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Thumbs up awk: how can I assign value to a shell variable inside awk?


Hi there,

I have a problem

a="abc:100:200"
I just want to split out the variable "a" into 3 variables:

e.g
echo $a | awk -F: '{
shell_val1=$1;
shell_val2=$2;
shell_val3=$3;
}'

I just don't want to call echo and awk 3 times:
e.g: shell_val1=`echo $a | awk -F: 'print $1'`

Is it possible to call echo and awk just one time (for better performance).

Thanks in advance.
 
Old 03-22-2010, 05:26 AM   #2
troop
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Code:
#!/bin/bash
string="abc:100:200";
IFS=":";
bar=( $string );
for (( i=0; i<${#bar[@]}; i++ )); do
  echo "["$i"] "${bar[$i]};
done;
fits so?

http://www.unix.com/shell-programmin...nto-array.html

Last edited by troop; 03-22-2010 at 05:40 AM.
 
Old 03-22-2010, 05:33 AM   #3
catkin
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For performance do it all in-shell
Code:
c@CW8:~$ a="abc:100:200"
c@CW8:~$ IFS=':'
c@CW8:~$ for x in $a
> do
> echo $x
> done
abc
100
200
c@CW8:~$ unset IFS
Alternatively
Code:
c@CW8:~$ a="abc:100:200"
c@CW8:~$ x=${a%%:*}
c@CW8:~$ echo $x
c@CW8:~$ a=${a#$x:}
c@CW8:~$ echo $a
100:200
c@CW8:~$ y=${a%%:*}
c@CW8:~$ echo $y
100
 
Old 03-22-2010, 06:41 AM   #4
grail
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Hey just in case you still want to use awk:

Code:
a="abc:100:200"

vars=($(awk 'BEGIN{var = "'$a'";gsub(/:/,"\n",var); print var}'))

for x in ${vars[@]}
do
    echo $x
done
 
Old 03-22-2010, 11:08 PM   #5
quanba
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Thanks you all, your solutions help me alot, not just about the current problem, but the way I write scripts.
 
Old 03-22-2010, 11:09 PM   #6
quanba
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thanks catkin, your 2nd solution is best fit
 
Old 03-23-2010, 02:18 AM   #7
grail
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quanba ... if finished with thread, please mark as SOLVED
 
  


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