Demo of bash/dash subshell when pipe to loop construct

pipe-to-loop.sh

[root@localhost couchbase-stuff]# cat tmp.sh
#! /bin/sh

count=0
/bin/ls /etc | while read f; do
  count=$((count + 1));
  echo $count $f;
done

# This prints 0 in bash and dash; prints count (e.g., 262) in ksh
echo "at the end, count is:  $count"

[root@localhost couchbase-stuff]# sh tmp.sh|tail
254 X11
255 xdg
256 xinetd.conf
257 xinetd.d
258 xml
259 yp.conf
260 yum
261 yum.conf
262 yum.repos.d
at the end, count is:  0