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Switching stdout redirection on-the-fly

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# 1  
Old 08-26-2008
Lightbulb Switching stdout redirection on-the-fly
I would like to build a shell script which runs a program and re-directs the output to a different file every minute. For example, the first minute the output get redirected to 1.txt, and the second minute to 2.txt, etc. I'm not sure how I would do this. To my understanding I should be able to use the & to allow program to run while the script continues execution, but how could I periodically re-direct stdout? I'm new to shell scripting and this seems to be a tricky problemSmilie Thanks!
# 2  
Old 08-26-2008
You can try the technique used in the following script (where a function simulates the program) :
Code:
program() {
   while (( count++ <= 60 ))
   do
      date +"$count %Y%d%d %H%M%S"
      sleep $(( $RANDOM % 10 ))
   done
}

initial_sec=$SECONDS
program |
while IFS= read line
do
   sec=$SECONDS
   (( min = (sec - initial_sec) / 60 + 1 ))
   out=$min.txt
   echo "$line" >> $out
done

Code:
> ls *.txt
/bin/ls: cannot access *.txt: No such file or directory
> date; sky.sh; date
Tue Aug 26 13:28:44     2008
Tue Aug 26 13:33:24     2008
> ls -l *.txt
-rw-r--r-- 1 Jean-Pierre Aucun 276 Aug 26 13:29 1.txt
-rw-r--r-- 1 Jean-Pierre Aucun 209 Aug 26 13:30 2.txt
-rw-r--r-- 1 Jean-Pierre Aucun 209 Aug 26 13:31 3.txt
-rw-r--r-- 1 Jean-Pierre Aucun 285 Aug 26 13:32 4.txt
-rw-r--r-- 1 Jean-Pierre Aucun 171 Aug 26 13:33 5.txt
> cat 1.txt
1 20082626 132844
2 20082626 132845
3 20082626 132854
4 20082626 132858
5 20082626 132900
6 20082626 132903
7 20082626 132905
8 20082626 132910
9 20082626 132918
10 20082626 132920
11 20082626 132922
12 20082626 132926
13 20082626 132928
14 20082626 132934
15 20082626 132940
> cat 5.txt
53 20082626 133243
54 20082626 133253
55 20082626 133254
56 20082626 133300
57 20082626 133301
58 20082626 133306
59 20082626 133310
60 20082626 133310
61 20082626 133319
>

Jean-Pierre.
# 3  
Old 08-27-2008
This is exactly the information I needed. Thanks a bunch!
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