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What's wrong with my bash code?

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Top Forums Shell Programming and Scripting What's wrong with my bash code?
# 1  
Old 11-08-2013
What's wrong with my bash code?
I want to let sleep 3 in the background and echo $i

Code:
pkglists="a b c d e f g"
f()
{
local i
set -- $pkglists 
[ ! -z "$1" ] && ((i +=2)) && sleep 3 &;echo $i
}
f

# 2  
Old 11-08-2013
This
Code:
[ ! -z "$1" ] && ((i +=2)) && sleep 3  &

gets executed in a new process in the background so a new $i get incremented in the background, but the $i that is local to the function does not get incremented in the foreground and therefore remains in its unitialized state.
# 3  
Old 11-08-2013
Quote:
Originally Posted by Scrutinizer
This
Code:
[ ! -z "$1" ] && ((i +=2)) && sleep 3  &

gets executed in a new process in the background so a new $i get incremented in the background, but the $i that is local to the function does not get incremented in the foreground and therefore remains in its unitialized state.
so how should I get it increased,

actually I want to get the pid of sleep 3

Code:
[ ! -z "$1" ] && ((i +=2)) && sleep 3 &

I want to get it's pid and put it in a lists something like
pid[i]= $!

how could I do
# 4  
Old 11-08-2013
read your shell's man page, here bash:
Quote:
Special Parameters
The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed.
.
.
.
! Expands to the process ID of the most recently executed background (asynchronous) command.
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