While Read Loop

Cited from For and Read-While Loops in Bash

while read line

do

  echo "$line"

done < list-of-dirs.txt

or 

while read line

do

  echo "$line"

done < <(cat list-of-dirs.txt)

Cited from While loop

while IFS= read -r line

do

  command1 on $line

  command2 on $line

  ..

  ....

  commandN

done < "/path/to/filename"

or

while IFS= read -r field1 filed2 field3 ... fieldN

do

  command1 on $field1

  command2 on $field1 and $field3

  ..

  ....

  commandN on $field1 ... $fieldN

done < "/path/to dir/file name with space"

"IFS is used to set field separator (default is while space). The -r option to read command disables backslash escaping (e.g., \n, \t). This is failsafe while read loop for reading text files."