SUBSHELL-IN-LINUX.txt

https://bash.cyberciti.biz/guide/What_is_a_Subshell%3F

https://www.linuxtopia.org/online_books/advanced_bash_scripting_guide/subshells.html

https://www.linuxjournal.com/content/bash-sub-shells --> IMP

https://docstore.mik.ua/orelly/unix3/korn/ch08_06.htm


#!/bin/bash
# allprofs.sh: Print all user profiles.

# This script written by Heiner Steven, and modified by the document author.

FILE=.bashrc  #  File containing user profile,
              #+ was ".profile" in original script.

for home in `awk -F: '{print $6}' /etc/passwd`
do
  [ -d "$home" ] || continue    # If no home directory, go to next.
  [ -r "$home" ] || continue    # If not readable, go to next.
  (cd $home; [ -e $FILE ] && less $FILE)
done

#  When script terminates, there is no need to 'cd' back to original directory,
#+ because 'cd $home' takes place in a subshell.

exit 0