I posted the following question to stackoverflow (http://stackoverflow.com/questions/30042157/why-cant-i-use-declare-r-inside-a-function-fo-mark-a-variable-readonly-while) and was advised the behavior I was witnessing was a bug in bash.
With GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu),#! /bin/bash set -u exec {FD1}>tmp1.txt declare -r FD1 echo "fd1: $FD1" # why does this work, function f1() { exec {FD2}>tmp2.txt readonly FD2 echo "fd2: $FD2" # this work, } f1 function f2() { exec {FD3}>tmp3.txt echo "fd3: $FD3" # and even this work, declare -r FD3 echo "fd3: $FD3" # when this complains: "FD3: unbound variable"? } f2Is this an actual bug, or am I missing something? -James