Shell Programming and Scripting

hi all , i am very new to unix and scripting language, can anybody explain to me what is the following statements mean? i cant find any exmaple on this. plese help... thanks a million.
p/s : It's tickle.


set about {}
set a "\[0-9\.\]" # is this a <= [1digit.] ??
set b "[a-zA-Z0-9_\.\]"
set c "[^a-zA-Z0-9_\.\]" # is this represent 2alphabet pls one digit or
#it's mean any digit or alphabet
set d "[ \t\f\n\r]" # i understand each statement meaning, but i
#cant figure out when all putting together.
set e "[^ \t\f\n\r]"

set about_a "^$d*about$d+($e)"
set about_b "^$d*($b+)$d+($b+)$d+\\((.+)\\)"
set about_c "^$d*($b+)$d+($e+)"
set about_d "^$d*($b+)$d+($b+)$d+($a+)"

I think you'll find all answers in following:

Code:

man  perlrequick

thank you mirusnet,
i just found some regexp examples also
i must study more.. thanks

one more question, there are similar command in tcl and perl, right, or even other scripting language also sharing the same command such as regexp? i just wonder.

You are right, there are some standards persistent in all languages.
But there can be difference of course related to the each of them.