i like bbedit better for taking notes...

sed & awk.... i luv u.....used for pattern matching and regular expressions.

s/die or do/do or die/

s/\([Dd]ie\) or \([Dd]o\)/\2 or \1/

important sed points:

sed operates as follows:

á         Each line of input is copied into a pattern space, an internal buffer where editing operations are performed.

á         All editing commands in a sed script are applied, in order, to each line of input.

á         Editing commands are applied to all lines (globally) unless line addressing restricts the lines affected.

á         If a command changes the input, subsequent commands and address tests will be applied to the current line in the pattern space, not the original input line.

á         The original input file is unchanged because the editing commands modify a copy of each original input line. The copy is sent to standard output (but can be redirected to a file).

á         sed also maintains the hold space, a separate buffer that can be used to save data for later retrieval.

sed syntax: [address[,address]][!]command [arguments]

if no address is provided, sed applies to each line, if one address it does it to the line matchin that address

Two comma-separated addresses:

First matching line and all succeeding lines up to and including a line matching the second address.

An address followed by !:

All lines that do not match the address.

/BSD/d Delete lines containing BSD.

/SAVE/!d Delete any line that doesn't contain SAVE.

a\ Append text after a line.

c\ Replace text (usually a text block).

i\ Insert text before a line.

d Delete lines.

s Make substitutions.

y Translate characters (like Unix tr).

With awk, you can:

á         Think of a text file as made up of records and fields in a textual database

á         Perform arithmetic and string operations

á         Use programming constructs such as loops and conditionals

á         Produce formatted reports

awk is basically a whole programming language

example awk:

/pattern/ { ++x }
END { print x }

(count the number of lines with 'pattern')

in the new awk, users are allowed to make their own functions.

awk hello world

awk 'BEGIN { printf "%2$s, %1$s\n", "world", "hello" }'