Here is my script:

echo "Defining aliases"
echo $$
echo "
s=screen
v=vlock -a
j=jobs
" | sed '/^$/d' | while read alias
do
  echo $$
  alias "$alias"
  alias | wc -l
done

And here is its output:

parthian@computer$ . aliases 
Defining aliases
3744
3744
4
3744
5
3744
6
parthian@computer$ ps -p $$
PID TTY          TIME CMD
3744 pts/1    00:00:03 bash
parthian@computer$ alias | wc -l
3

I'm flummoxed. This is some of the most straightforward code I've ever written, and it's not doing what it's supposed to do.

Here is my script:

echo "Defining aliases"
echo $$
echo "
s=screen
v=vlock -a
j=jobs
" | sed '/^$/d' | while read alias
do
  echo $$
  alias "$alias"
  alias | wc -l
done

And here is its output:

parthian@computer$ . aliases 
Defining aliases
3744
3744
4
3744
5
3744
6
parthian@computer$ ps -p $$
PID TTY          TIME CMD
3744 pts/1    00:00:03 bash
parthian@computer$ alias | wc -l
3

I'm flummoxed. This is some of the most straightforward code I've ever written, and it's not doing what it's supposed to do.

EDIT: When I change the echo lines from echo $$ to echo $$ $BASHPID, the second PID ($BASHPID) is different inside the loop, but $$ remains the same throughout. Could this be the issue?