Shell Programming and Scripting

Under IRIX 6.5, the Bourne shell is named /bin/bsh. I need to redirect output into a file reading loop, and retain values set within the loop based on processing that goes on within the loop for later processing. This code

Code:

#!/bin/bsh
k=1
cat file | while read k ; do
    echo "$k"
done
echo Final "$k"

produces the the lines of file followed by "Final 1". I know already this is a UUOC, but this version:

Code:

#!/bin/bsh
k=1
while read k ; do
    echo "$k"
done <file
echo Final "$k"

produces the same output. And this version

Code:

#!/bin/bsh
k=1
exec <file
while read k ; do
    echo "$k"
done
exec <&-
echo Final "$k"

just produces "Final " at the end.

Adding "export k" before or after k is set has no effect in any of the above.

Ideas?

Switch to ksh. If that's not possible, write the value of k to file each iteration of the loop. After the loop finishes, read the file to get the current value of k. Sorry, but that's about all the options you have. The bourne shell is running the loop in a sub-shell.

Actually, it can work in the Bourne shell. The mistake I made was to use the same variable for loop control and as the result. Specifically, the "exec" version works fine if reading a different variable than you're looking for at the end:

Code:

#!/bin/bsh
k=1
exec <file
while read kr ; do
    k="$kr"
done
exec <&-
echo "$k"

I guess it has something to do with not having a syntactic redirection into the while loop. When the final read "fails" at EOF, then $kr isn't set, but since $k was set, it comes through intact. Can anyone confirm or deny?