The man page of bash tells :
IFS The Internal Field Separator that is used for word splitting after expansion and to split lines into
words with the read builtin command. The default value is ``<space><tab><newline>''.
The default value of IFS is a space, a tab followed by a newline.
guru@unixschool:~$ echo "$IFS" guru@unixschool:~$ echo "$IFS" | cat -tve ^I$ $ guru@unixschool:~$When we echoed IFS for the first time, we could not see anything becuase they are special characters. On using the tve options of cat, we can see a space, followed by a ^I which is a tab character and then followed by a newline.