CODEWITHSUNDEEP
bashshell
Marouen
Marouen

Reputation: 945

append time values in bash for loop

I couldn't find what I am doing wrong in this script, I want the variable TimeVec to have all three time values. The script is supposed to save multiple running times of a program 

#!/bin/bash
TIMEFORMAT=%R
TimeVec=""
for run in 1 2 3; do(
    exec 3>&1 4>&2
    foo=$( { time sleep 1 1>&3 2>&4; }  2>&1 )
    exec 3>&- 4>&-
    TimeVec+=$foo
    echo $TimeVec
)
done
echo $TimeVec

this is what I get

1.001
1.003
1.003

EDIT

i would like the TimeVec variable to store all three time values.

Upvotes: 0

Views: 39

Answers (1)

Fred
Fred

Reputation: 6995

You are running your loop in a subshell due to the parentheses in do ( ... ) done. Each iteration gets its own subshell.

You want to use TimeVec in the parent shell, but the children processes cannot modify a variable in their parent process, and they cannot share the variable among them. So the variable is always null to begin with as seen by each iteration.

Upvotes: 1

Related Questions