<s>
The	B-Language
C	I-Language
standard	I-Language
library	I-Language
or	O
libc	B-Language
is	O
the	O
standard	B-Library
library	I-Library
for	O
the	O
C	B-Language
programming	I-Language
language	I-Language
,	O
as	O
specified	O
in	O
the	O
ISO	O
C	B-Language
standard	O
.	O
</s>
<s>
Starting	O
from	O
the	O
original	O
ANSI	O
C	B-Language
standard	O
,	O
it	O
was	O
developed	O
at	O
the	O
same	O
time	O
as	O
the	B-Language
C	I-Language
library	I-Language
POSIX	I-Language
specification	I-Language
,	O
which	O
is	O
a	O
superset	O
of	O
it	O
.	O
</s>
<s>
Since	O
ANSI	O
C	B-Language
was	O
adopted	O
by	O
the	O
International	O
Organization	O
for	O
Standardization	O
,	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
is	O
also	O
called	O
the	O
ISO	B-Language
C	I-Language
library	I-Language
.	O
</s>
<s>
The	B-Language
C	I-Language
standard	I-Language
library	I-Language
provides	O
macros	O
,	O
type	O
definitions	O
and	O
functions	O
for	O
tasks	O
such	O
as	O
string	O
handling	O
,	O
mathematical	O
computations	O
,	O
input/output	O
processing	O
,	O
memory	B-General_Concept
management	I-General_Concept
,	O
and	O
several	O
other	O
operating	B-General_Concept
system	I-General_Concept
services	O
.	O
</s>
<s>
The	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
of	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
is	O
declared	O
in	O
a	O
number	O
of	O
header	B-Language
files	I-Language
.	O
</s>
<s>
Each	O
header	B-Language
file	I-Language
contains	O
one	O
or	O
more	O
function	O
declarations	O
,	O
data	O
type	O
definitions	O
,	O
and	O
macros	O
.	O
</s>
<s>
After	O
a	O
long	O
period	O
of	O
stability	O
,	O
three	O
new	O
header	B-Language
files	I-Language
(	O
iso646.h	B-Language
,	O
wchar.h	B-Language
,	O
and	O
wctype.h	B-Language
)	O
were	O
added	O
with	O
Normative	O
Addendum	O
1	O
(	O
NA1	O
)	O
,	O
an	O
addition	O
to	O
the	O
C	B-Language
Standard	O
ratified	O
in	O
1995	O
.	O
</s>
<s>
Six	O
more	O
header	B-Language
files	I-Language
(	O
complex.h	O
,	O
fenv.h	O
,	O
inttypes.h	O
,	O
stdbool.h	O
,	O
stdint.h	O
,	O
and	O
tgmath.h	O
)	O
were	O
added	O
with	O
C99	B-Language
,	O
a	O
revision	O
to	O
the	O
C	B-Language
Standard	O
published	O
in	O
1999	O
,	O
and	O
five	O
more	O
files	O
(	O
stdalign.h	O
,	O
stdatomic.h	O
,	O
stdnoreturn.h	O
,	O
threads.h	O
,	O
and	O
uchar.h	O
)	O
with	O
C11	O
in	O
2011	O
.	O
</s>
<s>
In	O
total	O
,	O
there	O
are	O
now	O
29	O
header	B-Language
files	I-Language
:	O
</s>
<s>
Name	O
From	O
Description	O
<assert.h>	B-Language
Contains	O
the	O
assert	O
macro	O
,	O
used	O
to	O
assist	O
with	O
detecting	O
logical	O
errors	O
and	O
other	O
types	O
of	O
bugs	O
in	O
debugging	O
versions	O
of	O
a	O
program	O
.	O
</s>
<s>
<complex.h>	O
C99	B-Language
A	O
set	B-Language
of	I-Language
functions	I-Language
for	O
manipulating	O
complex	O
numbers	O
.	O
</s>
<s>
<ctype.h>	B-Language
Defines	O
set	B-Language
of	I-Language
functions	I-Language
used	O
to	O
classify	O
characters	O
by	O
their	O
types	O
or	O
to	O
convert	O
between	O
upper	O
and	O
lower	O
case	O
in	O
a	O
way	O
that	O
is	O
independent	O
of	O
the	O
used	O
character	B-General_Concept
set	I-General_Concept
(	O
typically	O
ASCII	B-Protocol
or	O
one	O
of	O
its	O
extensions	O
,	O
although	O
implementations	O
utilizing	O
EBCDIC	B-Language
are	O
also	O
known	O
)	O
.	O
</s>
<s>
<errno.h>	B-Error_Name
For	O
testing	O
error	O
codes	O
reported	O
by	O
library	B-Library
functions	I-Library
.	O
</s>
<s>
<fenv.h>	O
C99	B-Language
Defines	O
a	O
set	B-Language
of	I-Language
functions	I-Language
for	O
controlling	O
floating-point	B-Algorithm
environment	O
.	O
</s>
<s>
<float.h>	O
Defines	O
macro	O
constants	O
specifying	O
the	O
implementation-specific	O
properties	O
of	O
the	O
floating-point	B-Algorithm
library	O
.	O
</s>
<s>
<inttypes.h>	O
C99	B-Language
Defines	O
exact-width	O
integer	O
types	O
.	O
</s>
<s>
<iso646.h>	B-Language
NA1	O
Defines	O
several	B-Language
macros	I-Language
that	O
implement	O
alternative	O
ways	O
to	O
express	O
several	O
standard	O
tokens	O
.	O
</s>
<s>
For	O
programming	O
in	O
ISO	O
646	O
variant	O
character	B-General_Concept
sets	I-General_Concept
.	O
</s>
<s>
<locale.h>	O
Defines	O
localization	B-Language
functions	I-Language
.	O
</s>
<s>
<math.h>	O
Defines	O
common	B-Language
mathematical	I-Language
functions	I-Language
.	O
</s>
<s>
<setjmp.h>	B-Language
Declares	O
the	O
macros	O
setjmp	B-Language
and	O
longjmp	B-Language
,	O
which	O
are	O
used	O
for	O
non-local	O
exits	O
.	O
</s>
<s>
<signal.h>	B-Language
Defines	O
signal-handling	B-Language
functions	I-Language
.	O
</s>
<s>
<stdalign.h>	O
C11	O
For	O
querying	O
and	O
specifying	O
the	O
alignment	B-Application
of	O
objects	O
.	O
</s>
<s>
<stdarg.h>	B-Language
For	O
accessing	O
a	O
varying	O
number	O
of	O
arguments	O
passed	O
to	O
functions	O
.	O
</s>
<s>
<stdatomic.h>	O
C11	O
For	O
atomic	B-General_Concept
operations	I-General_Concept
on	O
data	O
shared	O
between	O
threads	B-Operating_System
.	O
</s>
<s>
<stdbool.h>	O
C99	B-Language
Defines	O
a	O
boolean	O
data	O
type	O
.	O
</s>
<s>
<stdint.h>	O
C99	B-Language
Defines	O
exact-width	O
integer	O
types	O
.	O
</s>
<s>
<stdio.h>   Defines core input and output functions <stdlib.h>   Defines numeric conversion functions, pseudo-random numbers generation functions, memory allocation, process control functions <stdnoreturn.h>  C11  For specifying non-returning functions <string.h>   Defines string-handling functions <tgmath.h>	O
C99	B-Language
Defines	O
type-generic	O
mathematical	O
functions	O
.	O
</s>
<s>
Three	O
of	O
the	O
header	B-Language
files	I-Language
(	O
complex.h	O
,	O
stdatomic.h	O
,	O
and	O
threads.h	O
)	O
are	O
conditional	O
features	O
that	O
implementations	O
are	O
not	O
required	O
to	O
support	O
.	O
</s>
<s>
The	O
POSIX	O
standard	O
added	O
several	O
nonstandard	O
C	B-Language
headers	I-Language
for	O
Unix-specific	O
functionality	O
.	O
</s>
<s>
Examples	O
include	O
fcntl.h	O
and	O
unistd.h.	O
</s>
<s>
A	O
number	O
of	O
other	O
groups	O
are	O
using	O
other	O
nonstandard	O
headers	O
–	O
the	O
GNU	B-Language
C	I-Language
Library	I-Language
has	O
alloca.h	O
,	O
and	O
HP	O
OpenVMS	B-Operating_System
has	O
the	O
va_count( )	O
function	O
.	O
</s>
<s>
On	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
the	O
authoritative	O
documentation	O
of	O
the	O
actually	O
implemented	O
API	B-Application
is	O
provided	O
in	O
the	O
form	O
of	O
man	B-Protocol
pages	I-Protocol
.	O
</s>
<s>
On	O
most	O
systems	O
,	O
man	B-Protocol
pages	I-Protocol
on	O
standard	B-Library
library	I-Library
functions	O
are	O
in	O
section3	O
;	O
section7	O
may	O
contain	O
some	O
more	O
generic	O
pages	O
on	O
underlying	O
concepts	O
(	O
e.g.	O
</s>
<s>
man	O
7	O
math_error	O
in	O
Linux	B-Application
)	O
.	O
</s>
<s>
Unix-like	B-Operating_System
systems	I-Operating_System
typically	O
have	O
a	O
C	B-Language
library	I-Language
in	O
shared	O
library	O
form	O
,	O
but	O
the	O
header	B-Language
files	I-Language
(	O
and	O
compiler	O
toolchain	O
)	O
may	O
be	O
absent	O
from	O
an	O
installation	O
so	O
C	B-Language
development	O
may	O
not	O
be	O
possible	O
.	O
</s>
<s>
The	O
C	B-Language
library	I-Language
is	O
considered	O
part	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
on	O
Unix-like	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
The	O
C	B-Language
functions	I-Language
,	O
including	O
the	O
ISO	O
C	B-Language
standard	O
ones	O
,	O
are	O
widely	O
used	O
by	O
programs	O
,	O
and	O
are	O
regarded	O
as	O
if	O
they	O
were	O
not	O
only	O
an	O
implementation	O
of	O
something	O
in	O
the	O
C	B-Language
language	I-Language
,	O
but	O
also	O
de	O
facto	O
part	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
interface	O
.	O
</s>
<s>
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
generally	O
cannot	O
function	O
if	O
the	O
C	B-Language
library	I-Language
is	O
erased	O
.	O
</s>
<s>
Further	O
,	O
the	O
kernel	O
itself	O
(	O
at	O
least	O
in	O
the	O
case	O
of	O
Linux	B-Application
)	O
operates	O
independently	O
of	O
any	O
libraries	O
.	O
</s>
<s>
On	O
Microsoft	O
Windows	O
,	O
the	O
core	O
system	O
dynamic	O
libraries	O
(	O
DLLs	O
)	O
provide	O
an	O
implementation	O
of	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
for	O
the	O
Microsoft	O
Visual	O
C++	B-Language
compiler	O
v6.0	O
;	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
for	O
newer	O
versions	O
of	O
the	O
Microsoft	O
VisualC++	B-Application
compiler	O
is	O
provided	O
by	O
each	O
compiler	O
individually	O
,	O
as	O
well	O
as	O
redistributable	O
packages	O
.	O
</s>
<s>
Compiled	O
applications	O
written	O
in	O
C	B-Language
are	O
either	O
statically	O
linked	O
with	O
a	O
C	B-Language
library	I-Language
,	O
or	O
linked	O
to	O
a	O
dynamic	O
version	O
of	O
the	O
library	O
that	O
is	O
shipped	O
with	O
these	O
applications	O
,	O
rather	O
than	O
relied	O
upon	O
to	O
be	O
present	O
on	O
the	O
targeted	O
systems	O
.	O
</s>
<s>
Functions	O
in	O
a	O
compiler	O
's	O
C	B-Language
library	I-Language
are	O
not	O
regarded	O
as	O
interfaces	O
to	O
Microsoft	O
Windows	O
.	O
</s>
<s>
Many	O
other	O
implementations	O
exist	O
,	O
provided	O
with	O
both	O
various	O
operating	B-General_Concept
systems	I-General_Concept
and	O
C	B-Language
compilers	O
.	O
</s>
<s>
Some	O
compilers	O
(	O
for	O
example	O
,	O
GCC	B-Application
)	O
provide	O
built-in	O
versions	O
of	O
many	O
of	O
the	O
functions	O
in	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
;	O
that	O
is	O
,	O
the	O
implementations	O
of	O
the	O
functions	O
are	O
written	O
into	O
the	O
compiled	O
object	B-Application
file	I-Application
,	O
and	O
the	O
program	O
calls	O
the	O
built-in	O
versions	O
instead	O
of	O
the	O
functions	O
in	O
the	O
C	B-Language
library	I-Language
shared	O
object	B-Application
file	I-Application
.	O
</s>
<s>
This	O
reduces	O
function-call	O
overhead	O
,	O
especially	O
if	O
function	O
calls	O
are	O
replaced	O
with	O
inline	O
variants	O
,	O
and	O
allows	O
other	O
forms	O
of	O
optimization	B-Application
(	O
as	O
the	O
compiler	O
knows	O
the	O
control-flow	O
characteristics	O
of	O
the	O
built-in	O
variants	O
)	O
,	O
but	O
may	O
cause	O
confusion	O
when	O
debugging	O
(	O
for	O
example	O
,	O
the	O
built-in	O
versions	O
cannot	O
be	O
replaced	O
with	O
instrumented	B-Application
variants	O
)	O
.	O
</s>
<s>
However	O
,	O
the	O
built-in	O
functions	O
must	O
behave	O
like	O
ordinary	O
functions	O
in	O
accordance	O
with	O
ISO	O
C	B-Language
.	O
The	O
main	O
implication	O
is	O
that	O
the	O
program	O
must	O
be	O
able	O
to	O
create	O
a	O
pointer	O
to	O
these	O
functions	O
by	O
taking	O
their	O
address	O
,	O
and	O
invoke	O
the	O
function	O
by	O
means	O
of	O
that	O
pointer	O
.	O
</s>
<s>
Under	O
FreeBSD	B-Operating_System
and	O
glibc	B-Language
,	O
some	O
functions	O
such	O
as	O
sin( )	O
are	O
not	O
linked	O
in	O
by	O
default	O
and	O
are	O
instead	O
bundled	O
in	O
the	O
mathematical	O
library	O
libm	O
.	O
</s>
<s>
POSIX	O
requires	O
that	O
the	O
c99	B-Language
compiler	O
supports	O
-lm	O
,	O
and	O
that	O
the	O
functions	O
declared	O
in	O
the	O
headers	O
math.h	O
,	O
complex.h	O
,	O
and	O
fenv.h	O
are	O
available	O
for	O
linking	O
if	O
-lm	O
is	O
specified	O
,	O
but	O
does	O
not	O
specify	O
if	O
the	O
functions	O
are	O
linked	O
by	O
default	O
.	O
</s>
<s>
musl	B-Language
satisfies	O
this	O
requirement	O
by	O
putting	O
everything	O
into	O
a	O
single	O
libc	B-Language
library	O
and	O
providing	O
an	O
empty	O
libm	O
.	O
</s>
<s>
According	O
to	O
the	O
C	B-Language
standard	O
the	O
macro	O
__STDC_HOSTED__	O
shall	O
be	O
defined	O
to	O
1	O
if	O
the	O
implementation	O
is	O
hosted	O
.	O
</s>
<s>
A	O
hosted	O
implementation	O
has	O
all	O
the	O
headers	O
specified	O
by	O
the	O
C	B-Language
standard	O
.	O
</s>
<s>
Some	O
functions	O
in	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
have	O
been	O
notorious	O
for	O
having	O
buffer	B-General_Concept
overflow	I-General_Concept
vulnerabilities	O
and	O
generally	O
encouraging	O
buggy	O
programming	O
ever	O
since	O
their	O
adoption	O
.	O
</s>
<s>
string-manipulation	B-Language
routines	I-Language
,	O
including	O
strcpy( )	O
and	O
strcat( )	O
,	O
for	O
lack	O
of	O
bounds	B-Data_Structure
checking	I-Data_Structure
and	O
possible	O
buffer	B-General_Concept
overflows	I-General_Concept
if	O
the	O
bounds	O
are	O
n't	O
checked	O
manually	O
;	O
</s>
<s>
string	O
routines	O
in	O
general	O
,	O
for	O
side-effects	O
,	O
encouraging	O
irresponsible	O
buffer	O
usage	O
,	O
not	O
always	O
guaranteeing	O
valid	O
null-terminated	B-Data_Structure
output	O
,	O
linear	O
length	O
calculation	O
;	O
</s>
<s>
printf( )	O
family	O
of	O
routines	O
,	O
for	O
spoiling	O
the	O
execution	B-General_Concept
stack	I-General_Concept
when	O
the	O
format	B-Language
string	I-Language
does	O
n't	O
match	O
the	O
arguments	O
given	O
.	O
</s>
<s>
This	O
fundamental	O
flaw	O
created	O
an	O
entire	O
class	O
of	O
attacks	O
:	O
format	B-Language
string	I-Language
attacks	O
;	O
</s>
<s>
gets( )	O
and	O
scanf( )	O
family	O
of	O
I/O	O
routines	O
,	O
for	O
lack	O
of	O
(	O
either	O
any	O
or	O
easy	O
)	O
input	O
length	O
checking	O
.	O
</s>
<s>
Except	O
the	O
extreme	O
case	O
with	O
gets( )	O
,	O
all	O
the	O
security	O
vulnerabilities	O
can	O
be	O
avoided	O
by	O
introducing	O
auxiliary	O
code	O
to	O
perform	O
memory	B-General_Concept
management	I-General_Concept
,	O
bounds	B-Data_Structure
checking	I-Data_Structure
,	O
input	O
checking	O
,	O
etc	O
.	O
</s>
<s>
This	O
is	O
often	O
done	O
in	O
the	O
form	O
of	O
wrappers	O
that	O
make	O
standard	B-Library
library	I-Library
functions	O
safer	O
and	O
easier	O
to	O
use	O
.	O
</s>
<s>
The	O
ISO	O
C	B-Language
committee	O
published	O
Technical	O
reports	O
TR	O
24731-1	O
and	O
is	O
working	O
on	O
TR	O
24731-2	O
to	O
propose	O
adoption	O
of	O
some	O
functions	O
with	O
bounds	B-Data_Structure
checking	I-Data_Structure
and	O
automatic	O
buffer	O
allocation	O
,	O
correspondingly	O
.	O
</s>
<s>
Despite	O
this	O
,	O
TR	O
24731-1	O
has	O
been	O
implemented	O
into	O
Microsoft	O
's	O
C	B-Language
standard	I-Language
library	I-Language
and	O
its	O
compiler	O
issues	O
warnings	O
when	O
using	O
old	O
"	O
insecure	O
"	O
functions	O
.	O
</s>
<s>
The	O
strerror( )	O
routine	O
is	O
criticized	O
for	O
being	O
thread	B-Operating_System
unsafe	I-Operating_System
and	O
otherwise	O
vulnerable	O
to	O
race	B-Operating_System
conditions	I-Operating_System
.	O
</s>
<s>
The	O
error	O
handling	O
of	O
the	O
functions	O
in	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
is	O
not	O
consistent	O
and	O
sometimes	O
confusing	O
.	O
</s>
<s>
According	O
to	O
the	O
Linux	B-Protocol
manual	I-Protocol
page	I-Protocol
math_error	O
,	O
"	O
The	O
current	O
(	O
version	O
2.8	O
)	O
situation	O
under	O
glibc	B-Language
is	O
messy	O
.	O
</s>
<s>
Some	O
also	O
set	O
errno	B-Error_Name
.	O
</s>
<s>
A	O
few	O
functions	O
set	O
errno	B-Error_Name
,	O
but	O
do	O
n't	O
raise	O
an	O
exception	O
.	O
</s>
<s>
The	O
original	O
C	B-Language
language	I-Language
provided	O
no	O
built-in	O
functions	O
such	O
as	O
I/O	O
operations	O
,	O
unlike	O
traditional	O
languages	O
such	O
as	O
COBOL	B-Application
and	O
Fortran	B-Application
.	O
</s>
<s>
Over	O
time	O
,	O
user	O
communities	O
of	O
C	B-Language
shared	O
ideas	O
and	O
implementations	O
of	O
what	O
is	O
now	O
called	O
C	B-Language
standard	I-Language
libraries	I-Language
.	O
</s>
<s>
Many	O
of	O
these	O
ideas	O
were	O
incorporated	O
eventually	O
into	O
the	O
definition	O
of	O
the	O
standardized	O
C	B-Language
language	I-Language
.	O
</s>
<s>
Both	O
Unix	B-Application
and	O
C	B-Language
were	O
created	O
at	O
T	O
's	O
Bell	O
Laboratories	O
in	O
the	O
late	O
1960s	O
and	O
early	O
1970s	O
.	O
</s>
<s>
During	O
the	O
1970s	O
the	O
C	B-Language
language	I-Language
became	O
increasingly	O
popular	O
.	O
</s>
<s>
By	O
the	O
beginning	O
of	O
the	O
1980s	O
compatibility	O
problems	O
between	O
the	O
various	O
C	B-Language
implementations	O
became	O
apparent	O
.	O
</s>
<s>
In	O
1983	O
the	O
American	O
National	O
Standards	O
Institute	O
(	O
ANSI	O
)	O
formed	O
a	O
committee	O
to	O
establish	O
a	O
standard	O
specification	O
of	O
C	B-Language
known	O
as	O
"	O
ANSI	O
C	B-Language
"	O
.	O
</s>
<s>
Part	O
of	O
the	O
resulting	O
standard	O
was	O
a	O
set	O
of	O
software	B-Library
libraries	I-Library
called	O
the	O
ANSI	B-Language
C	I-Language
standard	I-Language
library	I-Language
.	O
</s>
<s>
POSIX	O
,	O
as	O
well	O
as	O
SUS	O
,	O
specify	O
a	O
number	O
of	O
routines	O
that	O
should	O
be	O
available	O
over	O
and	O
above	O
those	O
in	O
the	O
basic	O
C	B-Language
standard	I-Language
library	I-Language
.	O
</s>
<s>
The	O
POSIX	O
specification	O
includes	O
header	B-Language
files	I-Language
for	O
,	O
among	O
other	O
uses	O
,	O
multi-threading	B-Operating_System
,	O
networking	B-Protocol
,	O
and	O
regular	B-Language
expressions	I-Language
.	O
</s>
<s>
These	O
are	O
often	O
implemented	O
alongside	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
functionality	O
,	O
with	O
varying	O
degrees	O
of	O
closeness	O
.	O
</s>
<s>
For	O
example	O
,	O
glibc	B-Language
implements	O
functions	O
such	O
as	O
fork	B-Language
within	O
libc.so,	O
but	O
before	O
NPTL	B-Application
was	O
merged	O
into	O
glibc	B-Language
it	O
constituted	O
a	O
separate	O
library	O
with	O
its	O
own	O
linker	O
flag	O
argument	O
.	O
</s>
<s>
Often	O
,	O
this	O
POSIX-specified	O
functionality	O
will	O
be	O
regarded	O
as	O
part	O
of	O
the	O
library	O
;	O
the	O
basic	O
C	B-Language
library	I-Language
may	O
be	O
identified	O
as	O
the	O
ANSI	O
or	O
ISO	B-Language
C	I-Language
library	I-Language
.	O
</s>
<s>
BSD	B-Operating_System
libc	B-Language
is	O
a	O
superset	O
of	O
the	O
POSIX	O
standard	B-Library
library	I-Library
supported	O
by	O
the	O
C	B-Language
libraries	I-Language
included	O
with	O
BSD	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
such	O
as	O
FreeBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
OpenBSD	B-Operating_System
and	O
macOS	B-Application
.	O
</s>
<s>
BSD	B-Operating_System
libc	B-Language
has	O
some	O
extensions	O
that	O
are	O
not	O
defined	O
in	O
the	O
original	O
standard	O
,	O
many	O
of	O
which	O
first	O
appeared	O
in	O
1994	O
's	O
4.4BSD	O
release	O
(	O
the	O
first	O
to	O
be	O
largely	O
developed	O
after	O
the	O
first	O
standard	O
was	O
issued	O
in	O
1989	O
)	O
.	O
</s>
<s>
Some	O
of	O
the	O
extensions	O
of	O
BSD	B-Operating_System
libc	B-Language
are	O
:	O
</s>
<s>
sys/queue.h	O
implementations	O
of	O
Linked	B-Data_Structure
list	I-Data_Structure
,	O
queues	B-Application
,	O
tail	O
queue	B-Application
,	O
etc	O
.	O
</s>
<s>
fgetln( )	O
defined	O
in	O
stdio.h.	O
</s>
<s>
Some	O
languages	O
include	O
the	O
functionality	O
of	O
the	O
standard	B-Language
C	I-Language
library	I-Language
in	O
their	O
own	O
libraries	O
.	O
</s>
<s>
The	O
C++	B-Language
language	I-Language
,	O
for	O
example	O
,	O
includes	O
the	O
functionality	O
of	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
in	O
the	O
namespace	O
std	O
(	O
e.g.	O
,	O
std::printf	B-Language
,	O
std::atoi	O
,	O
std::feof	O
)	O
,	O
in	O
header	B-Language
files	I-Language
with	O
similar	O
names	O
to	O
the	O
C	B-Language
ones	O
(	O
cstdio	B-Language
,	O
cmath	O
,	O
cstdlib	B-Language
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
Other	O
languages	O
that	O
take	O
similar	O
approaches	O
are	O
D	B-Application
,	O
Perl	B-Language
,	O
Ruby	B-Language
and	O
the	O
main	O
implementation	O
of	O
Python	B-Language
known	O
as	O
CPython	B-Language
.	O
</s>
<s>
In	O
Python	B-Language
2	O
,	O
for	O
example	O
,	O
the	O
built-in	O
file	O
objects	O
are	O
defined	O
as	O
"	O
implemented	O
using	O
C	B-Language
's	O
stdio	B-Language
package	O
"	O
,	O
so	O
that	O
the	O
available	O
operations	O
(	O
open	O
,	O
read	O
,	O
write	O
,	O
etc	O
.	O
)	O
</s>
<s>
are	O
expected	O
to	O
have	O
the	O
same	O
behavior	O
as	O
the	O
corresponding	O
C	B-Language
functions	I-Language
.	O
</s>
<s>
Rust	B-Application
has	O
a	O
crate	O
called	O
which	O
allows	O
several	O
C	B-Language
functions	I-Language
,	O
structs	O
,	O
and	O
other	O
type	O
definitions	O
to	O
be	O
used	O
.	O
</s>
<s>
The	B-Language
C	I-Language
standard	I-Language
library	I-Language
is	O
small	O
compared	O
to	O
the	O
standard	B-Library
libraries	I-Library
of	O
some	O
other	O
languages	O
.	O
</s>
<s>
The	O
C	B-Language
library	I-Language
provides	O
a	O
basic	O
set	O
of	O
mathematical	O
functions	O
,	O
string	O
manipulation	O
,	O
type	O
conversions	O
,	O
and	O
file	O
and	O
console-based	O
I/O	O
.	O
</s>
<s>
It	O
does	O
not	O
include	O
a	O
standard	O
set	O
of	O
"	O
container	B-Application
types	I-Application
"	O
like	O
the	O
C++	B-Language
Standard	B-Application
Template	I-Application
Library	I-Application
,	O
let	O
alone	O
the	O
complete	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
toolkits	O
,	O
networking	B-Protocol
tools	O
,	O
and	O
profusion	O
of	O
other	O
functionality	O
that	O
Java	B-Device
and	O
the	O
.NET	B-Application
Framework	I-Application
provide	O
as	O
standard	O
.	O
</s>
<s>
The	O
main	O
advantage	O
of	O
the	O
small	O
standard	B-Library
library	I-Library
is	O
that	O
providing	O
a	O
working	O
ISO	O
C	B-Language
environment	O
is	O
much	O
easier	O
than	O
it	O
is	O
with	O
other	O
languages	O
,	O
and	O
consequently	O
porting	O
C	B-Language
to	O
a	O
new	O
platform	O
is	O
comparatively	O
easy	O
.	O
</s>
