Some basic Syntax question

[rajeshatbuzz]

Hi,

Can you please explain me about following syntax...What does it mean by each of folliwing lines....

BAKIFS=$IFS

IFS=$(echo -en "\n\b")

exec 3<&0

exec 0<"$FILE"

exec 0<&3

[tetsujin]

Hi,

Can you please explain me about following syntax...What does it mean by each of folliwing lines....

BAKIFS=$IFS

Value of variable $IFS is stored in variable $BAKIFS (presumably so it can later be stored back into $IFS)

IFS=$(echo -en "\n\b")

$IFS is set to a string containing newline and backspace. ($IFS is a special variable - characters in the variable's value are used by the shell as delimiters for breaking up strings into command arguments.)

exec 3<&0

File descriptor zero (standard input) is duplicated as file descriptor 3 for input.

exec 0<"$FILE"

Standard input is redirected, and will be taken from the named file.

exec 0<&3

File descriptor 3 (a backup copy of the original FD 0) is dup'ed back on to file descriptor zero, restoring normal input.