As mentioned previously, a print statement contains a list
of items separated by commas. In the output, the items are normally
separated by single spaces. However, this doesn't need to be the case;
a single space is only the default. Any string of
characters may be used as the output field separator by setting the
built-in variable OFS. The initial value of this variable
is the string " "—that is, a single space.
The output from an entire print statement is called an
output record. Each print statement outputs one output
record, and then outputs a string called the output record separator
(or ORS). The initial
value of ORS is the string "\n"; i.e., a newline
character. Thus, each print statement normally makes a separate line.
In order to change how output fields and records are separated, assign
new values to the variables OFS and ORS. The usual
place to do this is in the BEGIN rule
(see BEGIN/END), so
that it happens before any input is processed. It can also be done
with assignments on the command line, before the names of the input
files, or using the -v command-line option
(see Options).
The following example prints the first and second fields of each input
record, separated by a semicolon, with a blank line added after each
newline:
$ awk 'BEGIN { OFS = ";"; ORS = "\n\n" }
> { print $1, $2 }' BBS-list
-| aardvark;555-5553
-|
-| alpo-net;555-3412
-|
-| barfly;555-7685
...
If the value of ORS does not contain a newline, the program's output
is run together on a single line.