<s>
AWK	B-Application
(	O
awk	B-Application
)	O
is	O
a	O
domain-specific	B-Language
language	I-Language
designed	O
for	O
text	O
processing	O
and	O
typically	O
used	O
as	O
a	O
data	B-General_Concept
extraction	I-General_Concept
and	O
reporting	O
tool	O
.	O
</s>
<s>
Like	O
sed	B-Application
and	O
grep	B-Application
,	O
it	O
is	O
a	O
filter	B-Application
,	O
and	O
is	O
a	O
standard	O
feature	O
of	O
most	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
The	O
AWK	B-Application
language	I-Application
is	O
a	O
data-driven	B-Application
scripting	B-Language
language	I-Language
consisting	O
of	O
a	O
set	O
of	O
actions	O
to	O
be	O
taken	O
against	O
streams	B-Architecture
of	O
textual	O
data	O
–	O
either	O
run	O
directly	O
on	O
files	O
or	O
used	O
as	O
part	O
of	O
a	O
pipeline	B-Operating_System
–	O
for	O
purposes	O
of	O
extracting	O
or	O
transforming	O
text	O
,	O
such	O
as	O
producing	O
formatted	O
reports	O
.	O
</s>
<s>
The	O
language	O
extensively	O
uses	O
the	O
string	O
datatype	O
,	O
associative	B-Application
arrays	I-Application
(	O
that	O
is	O
,	O
arrays	O
indexed	O
by	O
key	O
strings	O
)	O
,	O
and	O
regular	B-Language
expressions	I-Language
.	O
</s>
<s>
While	O
AWK	B-Application
has	O
a	O
limited	O
intended	O
application	B-General_Concept
domain	I-General_Concept
and	O
was	O
especially	O
designed	O
to	O
support	O
one-liner	B-Language
programs	I-Language
,	O
the	O
language	O
is	O
Turing-complete	O
,	O
and	O
even	O
the	O
early	O
Bell	O
Labs	O
users	O
of	O
AWK	B-Application
often	O
wrote	O
well-structured	O
large	O
AWK	B-Application
programs	O
.	O
</s>
<s>
AWK	B-Application
was	O
created	O
at	O
Bell	O
Labs	O
in	O
the	O
1970s	O
,	O
and	O
its	O
name	O
is	O
derived	O
from	O
the	O
surnames	O
of	O
its	O
authors	O
:	O
Alfred	O
Aho	O
,	O
Peter	O
Weinberger	O
,	O
and	O
Brian	O
Kernighan	O
.	O
</s>
<s>
The	O
acronym	O
is	O
pronounced	O
the	O
same	O
as	O
the	O
name	O
of	O
the	O
bird	O
species	O
auk	O
,	O
which	O
is	O
illustrated	O
on	O
the	O
cover	O
of	O
The	O
AWK	B-Application
Programming	I-Application
Language	I-Application
.	O
</s>
<s>
When	O
written	O
in	O
all	O
lowercase	O
letters	O
,	O
as	O
awk	B-Application
,	O
it	O
refers	O
to	O
the	O
Unix	B-Application
or	O
Plan	B-Operating_System
9	I-Operating_System
program	O
that	O
runs	O
scripts	O
written	O
in	O
the	O
AWK	B-Application
programming	I-Application
language	I-Application
.	O
</s>
<s>
AWK	B-Application
was	O
initially	O
developed	O
in	O
1977	O
by	O
Alfred	O
Aho	O
(	O
author	O
of	O
egrep	O
)	O
,	O
Peter	O
J	O
.	O
Weinberger	O
(	O
who	O
worked	O
on	O
tiny	O
relational	O
databases	O
)	O
,	O
and	O
Brian	O
Kernighan	O
.	O
</s>
<s>
AWK	B-Application
takes	O
its	O
name	O
from	O
their	O
respective	O
initials	O
.	O
</s>
<s>
According	O
to	O
Kernighan	O
,	O
one	O
of	O
the	O
goals	O
of	O
AWK	B-Application
was	O
to	O
have	O
a	O
tool	O
that	O
would	O
easily	O
manipulate	O
both	O
numbers	O
and	O
strings	O
.	O
</s>
<s>
AWK	B-Application
was	O
also	O
inspired	O
by	O
Marc	O
Rochkind	O
's	O
programming	O
language	O
that	O
was	O
used	O
to	O
search	O
for	O
patterns	O
in	O
input	O
data	O
,	O
and	O
was	O
implemented	O
using	O
yacc	B-Application
.	O
</s>
<s>
As	O
one	O
of	O
the	O
early	O
tools	O
to	O
appear	O
in	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
,	O
AWK	B-Application
added	O
computational	O
features	O
to	O
a	O
Unix	B-Operating_System
pipeline	I-Operating_System
besides	O
the	B-Device
Bourne	I-Device
shell	I-Device
,	O
the	O
only	O
scripting	B-Language
language	I-Language
available	O
in	O
a	O
standard	O
Unix	B-Application
environment	O
.	O
</s>
<s>
It	O
is	O
one	O
of	O
the	O
mandatory	O
utilities	O
of	O
the	O
Single	O
UNIX	B-Application
Specification	O
,	O
and	O
is	O
required	O
by	O
the	O
Linux	B-Application
Standard	I-Application
Base	I-Application
specification	O
.	O
</s>
<s>
AWK	B-Application
was	O
significantly	O
revised	O
and	O
expanded	O
in	O
1985	O
–	O
88	O
,	O
resulting	O
in	O
the	O
GNU	B-Operating_System
AWK	B-Application
implementation	O
written	O
by	O
Paul	O
Rubin	O
,	O
Jay	O
Fenlason	O
,	O
and	O
Richard	O
Stallman	O
,	O
released	O
in	O
1988	O
.	O
</s>
<s>
GNU	B-Operating_System
AWK	B-Application
may	O
be	O
the	O
most	O
widely	O
deployed	O
version	O
because	O
it	O
is	O
included	O
with	O
GNU-based	O
Linux	O
packages	O
.	O
</s>
<s>
GNU	B-Operating_System
AWK	B-Application
has	O
been	O
maintained	O
solely	O
by	O
Arnold	O
Robbins	O
since	O
1994	O
.	O
</s>
<s>
Brian	O
Kernighan	O
's	O
nawk	O
(	O
New	O
AWK	B-Application
)	O
source	O
was	O
first	O
released	O
in	O
1993	O
unpublicized	O
,	O
and	O
publicly	O
since	O
the	O
late	O
1990s	O
;	O
many	O
BSD	O
systems	O
use	O
it	O
to	O
avoid	O
the	O
GPL	O
license	O
.	O
</s>
<s>
AWK	B-Application
was	O
preceded	O
by	O
sed	B-Application
(	O
1974	O
)	O
.	O
</s>
<s>
They	O
share	O
the	O
line-oriented	O
,	O
data-driven	B-Application
paradigm	O
,	O
and	O
are	O
particularly	O
suited	O
to	O
writing	O
one-liner	B-Language
programs	I-Language
,	O
due	O
to	O
the	O
implicit	O
main	B-General_Concept
loop	I-General_Concept
and	O
current	O
line	O
variables	O
.	O
</s>
<s>
The	O
power	O
and	O
terseness	O
of	O
early	O
AWK	B-Application
programs	O
–	O
notably	O
the	O
powerful	O
regular	B-Language
expression	I-Language
handling	O
and	O
conciseness	O
due	O
to	O
implicit	O
variables	O
,	O
which	O
facilitate	O
one-liners	O
–	O
together	O
with	O
the	O
limitations	O
of	O
AWK	B-Application
at	O
the	O
time	O
,	O
were	O
important	O
inspirations	O
for	O
the	O
Perl	B-Language
language	I-Language
(	O
1987	O
)	O
.	O
</s>
<s>
In	O
the	O
1990s	O
,	O
Perl	B-Language
became	O
very	O
popular	O
,	O
competing	O
with	O
AWK	B-Application
in	O
the	O
niche	O
of	O
Unix	B-Application
text-processing	O
languages	O
.	O
</s>
<s>
An	O
AWK	B-Application
program	O
is	O
a	O
series	O
of	O
pattern	O
action	O
pairs	O
,	O
written	O
as	O
:	O
</s>
<s>
This	O
is	O
the	O
same	O
pattern-action	O
structure	O
as	O
sed	B-Application
.	O
</s>
<s>
In	O
addition	O
to	O
a	O
simple	O
AWK	B-Application
expression	O
,	O
such	O
as	O
foo	O
==	O
1	O
or	O
/	O
^	O
foo/	O
,	O
the	O
condition	O
can	O
be	O
BEGIN	O
or	O
END	O
causing	O
the	O
action	O
to	O
be	O
executed	O
before	O
or	O
after	O
all	O
records	O
have	O
been	O
read	O
,	O
or	O
pattern1	O
,	O
pattern2	O
which	O
matches	O
the	O
range	O
of	O
records	O
starting	O
with	O
a	O
record	O
that	O
matches	O
pattern1	O
up	O
to	O
and	O
including	O
the	O
record	O
that	O
matches	O
pattern2	O
before	O
again	O
trying	O
to	O
match	O
against	O
pattern1	O
on	O
subsequent	O
lines	O
.	O
</s>
<s>
In	O
addition	O
to	O
normal	O
arithmetic	O
and	O
logical	O
operators	O
,	O
AWK	B-Application
expressions	O
include	O
the	O
tilde	O
operator	O
,	O
~	O
,	O
which	O
matches	O
a	O
regular	B-Language
expression	I-Language
against	O
a	O
string	O
.	O
</s>
<s>
As	O
handy	O
syntactic	O
sugar	O
,	O
/regexp/	O
without	O
using	O
the	O
tilde	O
operator	O
matches	O
against	O
the	O
current	O
record	O
;	O
this	O
syntax	O
derives	O
from	O
sed	B-Application
,	O
which	O
in	O
turn	O
inherited	O
it	O
from	O
the	O
ed	B-Application
editor	O
,	O
where	O
/	O
is	O
used	O
for	O
searching	O
.	O
</s>
<s>
This	O
syntax	O
of	O
using	O
slashes	O
as	O
delimiters	B-Algorithm
for	O
regular	B-Language
expressions	I-Language
was	O
subsequently	O
adopted	O
by	O
Perl	B-Language
and	O
ECMAScript	B-Language
,	O
and	O
is	O
now	O
common	O
.	O
</s>
<s>
The	O
tilde	O
operator	O
was	O
also	O
adopted	O
by	O
Perl	B-Language
.	O
</s>
<s>
AWK	B-Application
commands	O
are	O
the	O
statements	O
that	O
are	O
substituted	O
for	O
action	O
in	O
the	O
examples	O
above	O
.	O
</s>
<s>
AWK	B-Application
commands	O
can	O
include	O
function	O
calls	O
,	O
variable	O
assignments	O
,	O
calculations	O
,	O
or	O
any	O
combination	O
thereof	O
.	O
</s>
<s>
AWK	B-Application
contains	O
built-in	O
support	O
for	O
many	O
functions	O
;	O
many	O
more	O
are	O
provided	O
by	O
the	O
various	O
flavors	O
of	O
AWK	B-Application
.	O
</s>
<s>
In	O
AWK	B-Application
,	O
records	O
are	O
broken	O
down	O
into	O
fields	O
,	O
and	O
these	O
can	O
be	O
displayed	O
separately	O
:	O
</s>
<s>
Although	O
these	O
fields	O
( $X	O
)	O
may	O
bear	O
resemblance	O
to	O
variables	O
(	O
the	O
$	O
symbol	O
indicates	O
variables	O
in	O
Perl	B-Language
)	O
,	O
they	O
actually	O
refer	O
to	O
the	O
fields	O
of	O
the	O
current	O
record	O
.	O
</s>
<s>
or	O
through	O
a	O
pipe	B-Operating_System
:	O
</s>
<s>
Awk	B-Application
's	O
built-in	O
variables	O
include	O
the	O
field	O
variables	O
:	O
$1	O
,	O
$2	O
,	O
$3	O
,	O
and	O
so	O
on	O
( $0	O
represents	O
the	O
entire	O
record	O
)	O
.	O
</s>
<s>
Stores	O
the	O
"	O
output	O
field	O
separator	O
"	O
,	O
which	O
separates	O
the	O
fields	O
when	O
Awk	B-Application
prints	O
them	O
.	O
</s>
<s>
Stores	O
the	O
"	O
output	O
record	O
separator	O
"	O
,	O
which	O
separates	O
the	O
output	O
records	O
when	O
Awk	B-Application
prints	O
them	O
.	O
</s>
<s>
Double	O
quotes	O
delimit	B-Algorithm
string	O
constants	O
.	O
</s>
<s>
In	O
a	O
format	O
similar	O
to	O
C	B-Language
,	O
function	O
definitions	O
consist	O
of	O
the	O
keyword	O
function	O
,	O
the	O
function	O
name	O
,	O
argument	O
names	O
and	O
the	O
function	O
body	O
.	O
</s>
<s>
Here	O
is	O
the	O
customary	O
"	O
Hello	O
,	O
world	O
"	O
program	O
written	O
in	O
AWK	B-Application
:	O
</s>
<s>
Count	O
words	O
in	O
the	O
input	O
and	O
print	O
the	O
number	O
of	O
lines	O
,	O
words	O
,	O
and	O
characters	O
(	O
like	O
wc	B-Application
)	O
:	O
</s>
<s>
s	O
is	O
incremented	O
by	O
the	O
numeric	O
value	O
of	O
$NF	O
,	O
which	O
is	O
the	O
last	O
word	O
on	O
the	O
line	O
as	O
defined	O
by	O
AWK	B-Application
's	O
field	O
separator	O
(	O
by	O
default	O
,	O
white-space	O
)	O
.	O
</s>
<s>
Adding	O
zero	O
to	O
a	O
variable	O
is	O
an	O
AWK	B-Application
idiom	O
for	O
coercing	O
it	O
from	O
a	O
string	O
to	O
a	O
numeric	O
value	O
.	O
</s>
<s>
The	O
printf	B-Language
function	O
emulates	O
the	O
standard	O
C	B-Language
printf	B-Language
and	O
works	O
similarly	O
to	O
the	O
print	O
command	O
described	O
above	O
.	O
</s>
<s>
The	O
pattern	O
to	O
match	O
,	O
however	O
,	O
works	O
as	O
follows	O
:	O
NR	O
is	O
the	O
number	O
of	O
records	O
,	O
typically	O
lines	O
of	O
input	O
,	O
AWK	B-Application
has	O
so	O
far	O
read	O
,	O
i.e.	O
</s>
<s>
prints	O
lines	O
of	O
input	O
from	O
the	O
first	O
line	O
matching	O
the	O
regular	B-Language
expression	I-Language
^	O
--cut	O
here--	O
$	O
,	O
that	O
is	O
,	O
a	O
line	O
containing	O
only	O
the	O
phrase	O
"	O
--cut	O
here--	O
"	O
,	O
to	O
the	O
end	O
.	O
</s>
<s>
Word	O
frequency	O
using	O
associative	B-Application
arrays	I-Application
:	O
</s>
<s>
Note	O
that	O
separators	O
can	O
be	O
regular	B-Language
expressions	I-Language
.	O
</s>
<s>
tolower	O
was	O
an	O
addition	O
to	O
the	O
One	O
True	O
awk	B-Application
(	O
see	O
below	O
)	O
made	O
after	O
the	O
book	O
was	O
published	O
.	O
</s>
<s>
The	O
first	O
one	O
uses	O
the	B-Device
Bourne	I-Device
shell	I-Device
to	O
make	O
a	O
shell	O
script	O
that	O
does	O
everything	O
.	O
</s>
<s>
The	O
$pattern	O
in	O
the	O
awk	B-Application
command	O
is	O
not	O
protected	O
by	O
single	O
quotes	O
so	O
that	O
the	O
shell	O
does	O
expand	O
the	O
variable	O
but	O
it	O
needs	O
to	O
be	O
put	O
in	O
double	O
quotes	O
to	O
properly	O
handle	O
patterns	O
containing	O
spaces	O
.	O
</s>
<s>
awk	B-Application
has	O
no	O
explicit	O
concatenation	O
operator	O
;	O
two	O
adjacent	O
strings	O
concatenate	O
them	O
.	O
</s>
<s>
This	O
shell	O
script	O
accesses	O
the	O
environment	O
directly	O
from	O
within	O
awk	B-Application
:	O
</s>
<s>
This	O
is	O
a	O
shell	O
script	O
that	O
uses	O
ENVIRON	O
,	O
an	O
array	O
introduced	O
in	O
a	O
newer	O
version	O
of	O
the	O
One	O
True	O
awk	B-Application
after	O
the	O
book	O
was	O
published	O
.	O
</s>
<s>
The	O
shell	O
script	O
makes	O
an	O
environment	O
variable	O
pattern	O
containing	O
the	O
first	O
argument	O
,	O
then	O
drops	O
that	O
argument	O
and	O
has	O
awk	B-Application
look	O
for	O
the	O
pattern	O
in	O
each	O
file	O
.	O
</s>
<s>
Note	O
that	O
a	O
regular	B-Language
expression	I-Language
is	O
just	O
a	O
string	O
and	O
can	O
be	O
stored	O
in	O
variables	O
.	O
</s>
<s>
The	O
next	O
way	O
uses	O
command-line	O
variable	O
assignment	O
,	O
in	O
which	O
an	O
argument	O
to	O
awk	B-Application
can	O
be	O
seen	O
as	O
an	O
assignment	O
to	O
a	O
variable	O
:	O
</s>
<s>
awk	B-Application
-v	O
pattern	O
=	O
"	O
$pattern	O
"	O
...	O
)	O
.	O
</s>
<s>
Finally	O
,	O
this	O
is	O
written	O
in	O
pure	O
awk	B-Application
,	O
without	O
help	O
from	O
a	O
shell	O
or	O
without	O
the	O
need	O
to	O
know	O
too	O
much	O
about	O
the	O
implementation	O
of	O
the	O
awk	B-Application
script	O
(	O
as	O
the	O
variable	O
assignment	O
on	O
command	O
line	O
one	O
does	O
)	O
,	O
but	O
is	O
a	O
bit	O
lengthy	O
:	O
</s>
<s>
ARGC	O
,	O
the	O
number	O
of	O
arguments	O
,	O
is	O
always	O
guaranteed	O
to	O
be	O
≥1	O
,	O
as	O
ARGV[0]	O
is	O
the	O
name	O
of	O
the	O
command	O
that	O
executed	O
the	O
script	O
,	O
most	O
often	O
the	O
string	O
"	O
awk	B-Application
"	O
.	O
</s>
<s>
awk	B-Application
only	O
checks	O
to	O
see	O
if	O
it	O
should	O
read	O
from	O
standard	O
input	O
before	O
it	O
runs	O
the	O
command	O
.	O
</s>
<s>
If	O
you	O
explicitly	O
set	O
ARGC	O
to	O
1	O
so	O
that	O
there	O
are	O
no	O
arguments	O
,	O
awk	B-Application
will	O
simply	O
quit	O
because	O
it	O
feels	O
there	O
are	O
no	O
more	O
input	O
files	O
.	O
</s>
<s>
On	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
self-contained	O
AWK	B-Application
scripts	O
can	O
be	O
constructed	O
using	O
the	O
shebang	B-Operating_System
syntax	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
script	O
that	O
prints	O
the	O
content	O
of	O
a	O
given	O
file	O
may	O
be	O
built	O
by	O
creating	O
a	O
file	O
named	O
print.awk	O
with	O
the	O
following	O
content	O
:	O
</s>
<s>
The	O
-f	O
tells	O
AWK	B-Application
that	O
the	O
argument	O
that	O
follows	O
is	O
the	O
file	O
to	O
read	O
the	O
AWK	B-Application
program	O
from	O
,	O
which	O
is	O
the	O
same	O
flag	O
that	O
is	O
used	O
in	O
sed	B-Application
.	O
</s>
<s>
AWK	B-Application
was	O
originally	O
written	O
in	O
1977	O
and	O
distributed	O
with	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
.	O
</s>
<s>
The	O
language	O
is	O
described	O
in	O
the	O
book	O
The	O
AWK	B-Application
Programming	I-Application
Language	I-Application
,	O
published	O
1988	O
,	O
and	O
its	O
implementation	O
was	O
made	O
available	O
in	O
releases	O
of	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
.	O
To	O
avoid	O
confusion	O
with	O
the	O
incompatible	O
older	O
version	O
,	O
this	O
version	O
was	O
sometimes	O
called	O
"	O
new	O
awk	B-Application
"	O
or	O
nawk	O
.	O
</s>
<s>
This	O
implementation	O
was	O
released	O
under	O
a	O
free	B-License
software	I-License
license	I-License
in	O
1996	O
and	O
is	O
still	O
maintained	O
by	O
Brian	O
Kernighan	O
(	O
see	O
external	O
links	O
below	O
)	O
.	O
</s>
<s>
Old	O
versions	O
of	O
Unix	B-Application
,	O
such	O
as	O
UNIX/32V	B-Operating_System
,	O
included	O
awkcc	O
,	O
which	O
converted	O
AWK	B-Application
to	O
C	B-Language
.	O
Kernighan	O
wrote	O
a	O
program	O
to	O
turn	O
awk	B-Application
into	O
C++	B-Language
;	O
its	O
state	O
is	O
not	O
known	O
.	O
</s>
<s>
BWK	O
awk	B-Application
,	O
also	O
known	O
as	O
nawk	O
,	O
refers	O
to	O
the	O
version	O
by	O
Brian	O
Kernighan	O
.	O
</s>
<s>
It	O
has	O
been	O
dubbed	O
the	O
"	O
One	O
True	O
AWK	B-Application
"	O
because	O
of	O
the	O
use	O
of	O
the	O
term	O
in	O
association	O
with	O
the	O
book	O
that	O
originally	O
described	O
the	O
language	O
and	O
the	O
fact	O
that	O
Kernighan	O
was	O
one	O
of	O
the	O
original	O
authors	O
of	O
AWK	B-Application
.	O
</s>
<s>
FreeBSD	B-Operating_System
refers	O
to	O
this	O
version	O
as	O
one-true-awk	O
.	O
</s>
<s>
This	O
version	O
is	O
used	O
by	O
,	O
for	O
example	O
,	O
Android	B-Application
,	O
FreeBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
OpenBSD	B-Operating_System
,	O
macOS	B-Application
,	O
and	O
illumos	B-Application
.	O
</s>
<s>
gawk	O
(	O
GNU	B-Operating_System
awk	B-Application
)	O
is	O
another	O
free-software	O
implementation	O
and	O
the	O
only	O
implementation	O
that	O
makes	O
serious	O
progress	O
implementing	O
internationalization	B-General_Concept
and	I-General_Concept
localization	I-General_Concept
and	O
TCP/IP	O
networking	O
.	O
</s>
<s>
Some	O
Linux	B-Application
distributions	I-Application
include	O
gawk	O
as	O
their	O
default	O
AWK	B-Application
implementation	O
.	O
</s>
<s>
mawk	O
is	O
a	O
very	O
fast	O
AWK	B-Application
implementation	O
by	O
Mike	O
Brennan	O
based	O
on	O
a	O
bytecode	O
interpreter	O
.	O
</s>
<s>
libmawk	O
is	O
a	O
fork	O
of	O
mawk	O
,	O
allowing	O
applications	O
to	O
embed	O
multiple	O
parallel	O
instances	O
of	O
awk	B-Application
interpreters	O
.	O
</s>
<s>
awka	O
(	O
whose	O
front	O
end	O
is	O
written	O
atop	O
the	O
mawk	O
program	O
)	O
is	O
another	O
translator	O
of	O
AWK	B-Application
scripts	O
into	O
C	B-Language
code	O
.	O
</s>
<s>
When	O
compiled	B-Language
,	O
statically	O
including	O
the	O
author	O
's	O
libawka.a	O
,	O
the	O
resulting	O
executables	O
are	O
considerably	O
sped	O
up	O
and	O
,	O
according	O
to	O
the	O
author	O
's	O
tests	O
,	O
compare	O
very	O
well	O
with	O
other	O
versions	O
of	O
AWK	B-Application
,	O
Perl	B-Language
,	O
or	O
Tcl	B-Operating_System
.	O
</s>
<s>
tawk	O
(	O
Thompson	O
AWK	B-Application
)	O
is	O
an	O
AWK	B-Application
compiler	B-Language
for	O
Solaris	B-Application
,	O
DOS	B-Device
,	O
OS/2	B-Application
,	O
and	O
Windows	B-Application
,	O
previously	O
sold	O
by	O
Thompson	O
Automation	O
Software	O
(	O
which	O
has	O
ceased	O
its	O
activities	O
)	O
.	O
</s>
<s>
Jawk	O
is	O
a	O
project	O
to	O
implement	O
AWK	B-Application
in	O
Java	B-Language
,	O
hosted	O
on	O
SourceForge	O
.	O
</s>
<s>
Extensions	O
to	O
the	O
language	O
are	O
added	O
to	O
provide	O
access	O
to	O
Java	B-Language
features	O
within	O
AWK	B-Application
scripts	O
(	O
i.e.	O
,	O
Java	B-Language
threads	O
,	O
sockets	O
,	O
collections	O
,	O
etc	O
.	O
</s>
<s>
The	O
XMLgawk	O
extension	O
was	O
integrated	O
into	O
the	O
official	O
GNU	B-Operating_System
Awk	B-Application
release	O
4.1.0	O
.	O
</s>
<s>
QSEAWK	O
is	O
an	O
embedded	O
AWK	B-Application
interpreter	O
implementation	O
included	O
in	O
the	O
QSE	O
library	O
that	O
provides	O
embedding	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
for	O
C	B-Language
and	O
C++	B-Language
.	O
</s>
<s>
BusyBox	B-Application
includes	O
an	O
AWK	B-Application
implementation	O
written	O
by	O
Dmitry	O
Zakharov	O
.	O
</s>
<s>
CLAWK	O
by	O
Michael	O
Parker	O
provides	O
an	O
AWK	B-Application
implementation	O
in	O
Common	B-Language
Lisp	I-Language
,	O
based	O
upon	O
the	O
regular	B-Language
expression	I-Language
library	O
of	O
the	O
same	O
author	O
.	O
</s>
