Sh, bash and csh

From The System Administrator Zone

How to access a data which is set in child shell script from a parent script

The bourne shell cannot use 'export' to access the variables outside a loop. With a Bourne shell you need to reassign the descriptors, so no pipeline or redirection in loop is involved!

Therefore, use the following statements as required!

  exec 3<&0
  exec<file
  while read line; do
  x=$line
  done
  exec 0<&3

In the kourne shell use

 execute < &CONFIG_FILE

 while read tmpLine
 do 

 ...

 Done 

Command line redirection

log_file=/tmp/command_log_file
command | tee -a "$log_file"

tee has two output streams. One is an input to a file (using -a to append rather than overwrite) while the second copyies the input to standard output.