Shell scripting input redirection oddities

Question

Can anyone explain this behavior? Running:

#!/bin/sh
echo \"hello world\" | read var1 var2
echo $var1
echo $var2

results in nothing being o

Answer 1

Try:

echo "hello world" | (read var1 var2 ; echo $var1 ; echo $var2 )

The problem, as multiple people have stated, is that var1 and var2 are created in a subshell environment that is destroyed when that subshell exits. The above avoids destroying the subshell until the result has been echo'd. Another solution is:

result=`echo "hello world"`
read var1 var2 <