/** @file ../include/ctype.h
@internalComponent
*/
/** @fn isalnum(int c)
@param c
@return The isalnum function returns zero if the character is not alphanumeric and
returns non-zero if the character tests true.
The function isalnum returns non-zero if 'c' is alphanumeric i.e. it belongs to class alnum(see defns for definition). In other words, it returns non-zero if the test for isalpha or isdigit is non-zero, irrespective of the program's current locale. For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class alnum,
irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isalnum()
#include<stdio.h> //printf()
void test_isalnum()
{
int arr[]={'8',0xe1,'5','Z',0xfd};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isalnum(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not alphanumeric", arr[i]);
}
else
{
printf("
%c is an alphanumeric ", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
a is an alphanumeric
á is an alphanumeric
5 is an alphanumeric
Z is an alphanumeric
ý is an alphanumeric
@endcode
@see isalpha()
@see isdigit()
@see iswalnum()
@publishedAll
@externallyDefinedApi
*/
/** @fn isalpha(int c)
@param c
@return The isalpha function returns non-zero if the character is an alphabet and zero otherwise.
The isalpha function returns non-zero if 'c' is an alphabet i.e. it belongs to class alpha (see defns for definition). In other words, it returns non-zero if the test for isupper or islower is non-zero,irrespective of the program's current locale. The function will return non-zero for also those characters that are alphabets and cannot be categorised as upper or lower case.
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class alpha, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isalpha()
#include<stdio.h> //printf()
void test_isalpha()
{
int arr[]={'a',0xe1,'5','Z',0xfd};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isalpha(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not an alphabet", arr[i]);
}
else
{
printf("
%c is an alphabet", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
a is an alphabet
á is an alphabet
5 is not an alphabet
Z is an alphabet
ý is an alphabet
@endcode
@see islower()
@see isupper()
@see iswalpha()
@publishedAll
@externallyDefinedApi
*/
/** @fn iscntrl(int c)
@param c
@return The iscntrl function returns non-zero if 'c' is control character and zero otherwise.
The iscntrl function tests if 'c' is a control character i.e. it belongs to class cntrl(see defns for definition).
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class cntrl, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //iscntrl()
#include<stdio.h> //printf()
int test_iscntrl()
{
int arr[]={0x7F,’9’,’A’,’$’,’\a’ };
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = iscntrl(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not cntrl char ", arr[i]);
}
else
{
printf("
%c is cntrl char", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
is cntrl char
9 is not cntrl char
A is not cntrl char
$ is not cntrl char
is cntrl char
@endcode
@see iswcntrl()
@publishedAll
@externallyDefinedApi
*/
/** @fn isdigit(int c)
@param c
@return The isdigit function returns non-zero if the character is a digit and zero otherwise.
The isdigit function tests if ’c’ is a decimal digit character. Regardless of locale, this includes the following characters only:
@code
‘‘0’’ ‘‘1’’ ‘‘2’’ ‘‘3’’ ‘‘4’’
‘‘5’’ ‘‘6’’ ‘‘7’’ ‘‘8’’ ‘‘9’’
@endcode
Examples:
@code
#include<ctype.h> //isdigit()
#include<stdio.h> //printf()
void test_isdigit()
{
int arr[]={'8',0xe1,'5','Z',0xfd};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isdigit(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not a digit", arr[i]);
}
else
{
printf("
%c is a digit", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
8 is a digit
á is not a digit
5 is a digit
Z is not a digit
ý is not a digit
@endcode
@see iswdigit()
@see defns()
@publishedAll
@externallyDefinedApi
*/
/** @fn isgraph(int c)
@param c
@return The isgraph function returns non-zero if 'c' has a visible representation and zero otherwise.
The isgraph function returns non-zero if 'c' has visible representation i.e. it belongs to class graph(see defns for definition). It does not consider characters classified under class space
and class cntrl (see defns for definition).
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class graph, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isgraph()
#include<stdio.h> //printf()
int test_isgraph()
{
int arr[]={’n’,’\f’, ’6’, ’ ’};
int i = 0;
int size = 4;
for( i=0; i<size; i++)
{
int ret = isgraph(arr[i]); //call to API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not visible char ", arr[i]);
}
else
{
printf("
%c is visible char", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
n is visible char
is not visible char
6 is visible char
is not visible char
@endcode
@see iswgraph()
@publishedAll
@externallyDefinedApi
*/
/** @fn islower(int c)
@param c
@return The islower function returns non-zero is 'c' is a lower-case alphabet and zero otherwise.
The islower function tests if 'c' belongs to the set of lower-case letters i.e. it belongs to class lower(see defns for definition).
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class lower, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //islower()
#include<stdio.h> //printf()
int test_islower()
{
int arr[]={0x0126,0xee,'r','9','g'};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = islower(arr[i]); //call to the API with chars in the arr[]
if( (!ret) != 0 )
{
printf("
%c is not in lower-case ", arr[i]);
}
else
{
printf("
%c is in lower-case", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
& is not in lower-case
î is in lower-case
r is in lower-case
9 is not in lower-case
g is in lower-case
@endcode
@see iswlower()
@see tolower()
@publishedAll
@externallyDefinedApi
*/
/** @fn isprint(int c)
@param c
@return The isprint function returns non-zero if 'c' is printable and zero otherwise.
The isprint function returns true if 'c' is a printable character. It considers characters under class space, but characters falling under class cntrl will not be considered(see defns for definition of these classes).
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class print(see defns for definition), irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isprint()
#include<stdio.h> //printf()
int test_isprint()
{
int arr[]={’n’,’\f’, 0xe1, ’6’, ’ ’};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isprint(arr[i]); //call to the API with the chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not printable char ", arr[i]);
}
else
{
printf("
%c is printable char", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
n is printable char
is not printable char
á is not printable char
6 is printable char
is printable char
@endcode
@see iswprint()
@publishedAll
@externallyDefinedApi
*/
/** @fn ispunct(int c)
@param c
@return The ispunct function returns non-zero if 'c' is a punctuation character and zero otherwise.
The ispunct function tests if 'c' is a punctuation character i.e. it belongs to class punct(see defns for definition). Characters under class space
or a
character for which isalnum is true(non-zero) are excluded. In other words, it tests for punctuation characters.
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class punct, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //ispunct()
#include<stdio.h> //printf()
int test_ispunct()
{
int arr[]={0x3003,'3',0x301C,'*', '+'};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = ispunct(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
0x%x is not a punc char ", arr[i]);
}
else
{
printf("
0x%x is a punc char", arr[i]);
}
}
printf("
");
return 0;
}
@endcode
Output
@code
0x3003 is a punc char
0x33 is not a punc char
0x301c is a punc char
0x2a is a punc char
0x2b is a punc char
@endcode
@see iswpunct()
@publishedAll
@externallyDefinedApi
*/
/** @fn isspace(int c)
@param c
@return The isspace function returns non-zero if 'c' is space character and zero otherwise.
The isspace function tests if 'c' is from among white-space characters i.e. it belongs to class space(see defns for definition).
This includes the following standard characters:
SPACE
FORM-FEED
NEWLINE
CARRIAGE-RETURN
TAB
VERTICAL-TAB
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class space, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isspace()
#include<stdio.h> //printf()
int test_isspace()
{
int arr[]={'
','0','w','R',0x3000,' '};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isspace(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not space char ", arr[i]);
}
else
{
printf("
%c is space char", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
is space char
0 is not space char
w is not space char
R is not space char
is space char
@endcode
@see iswspace()
@publishedAll
@externallyDefinedApi
*/
/** @fn isupper(int c)
@param c
@return The isupper function returns non-zero if 'c' is in upper case and zero otherwise.
The isupper function tests if 'c' is an upper-case alphabet i.e. it belongs to class upper(see defns for definition).
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF.
The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class upper, irrespective of the locale they belong to.
Examples:
@code
#include<ctype.h> //isupper()
#include<stdio.h> //printf()
int test_isupper()
{
int arr[]={0x0126,'G','7','B',0x3041};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isupper(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not in upper-case ", arr[i]);
}
else
{
printf("
%c is in upper-case", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
& is in upper-case
G is in upper-case
7 is not in upper-case
B is in upper-case
A is in upper-case
@endcode
@see iswupper()
@see toupper()
@publishedAll
@externallyDefinedApi
*/
/** @fn isxdigit(int c)
@param c
@return The isxdigit function returns non-zero if 'c' is a character used for hex-representation and zero otherwise. The iswxdigit function should be used instead.
The isxdigit function tests if ’c’ is a hexadecimal-digit character. Regardless of locale, this includes the following characters only:
@code
‘‘0’’ ‘‘1’’ ‘‘2’’ ‘‘3’’ ‘‘4’’
‘‘5’’ ‘‘6’’ ‘‘7’’ ‘‘8’’ ‘‘9’’
‘‘A’’ ‘‘B’’ ‘‘C’’ ‘‘D’’ ‘‘E’’
‘‘F’’ ‘‘a’’ ‘‘b’’ ‘‘c’’ ‘‘d’’
‘‘e’’ ‘‘f’’
@endcode
Examples:
@code
#include<ctype.h> //isxdigit()
#include<stdio.h> //printf()
int test_isxdigit()
{
int arr[]={'F','a','M','9','2'};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = isxdigit(arr[i]); //call to the API with chars in arr[]
if( (!ret) != 0 )
{
printf("
%c is not hex-digit ", arr[i]);
}
else
{
printf("
%c is hex-digit", arr[i]);
}
}
printf("
");
}
@endcode
Output
@code
F is hex-digit
a is hex-digit
M is not hex-digit
9 is hex-digit
2 is hex-digit
@endcode
@see iswxdigit()
@see defns()
@publishedAll
@externallyDefinedApi
*/
/** @fn tolower(int c)
@param c
@return If the argument is an upper-case letter, the tolower function returns the corresponding lower-case letter if there
is one; otherwise the argument is returned unchanged. The wide version, towlower , should normally be used instead.
The tolower function converts an upper-case letter to the corresponding lower-case
letter.
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF .
The functionality of this API is independent of the program's current locale.
Examples:
@code
#include<ctype.h> //tolower()
#include<stdio.h> //printf()
int test_tolower ()
{
struct st
{
int input;
int output;
};
struct st arr[]=
{
{ 'Q', 'q' },
{ 'g' , 'g' },
{ '9' , '9' },
{ '%' , '%' },
{ ' ' , ' ' },
};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = tolower(arr[i].input);//call to the API with the chars in the arr[]
if( ret != arr[i].output )
{
printf("
%c cannot convert ", arr[i].input);
}
else
{
printf("
%c ", arr[i].output);
}
}
printf("
");
}
@endcode
Output
@code
q
g
9
%
@endcode
@see islower()
@see towlower()
@see defns()
@publishedAll
@externallyDefinedApi
*/
/** @fn toupper(int c)
@param c
@return If the argument is a lower-case letter, the toupper function returns the corresponding upper-case letter if there
is one; otherwise the argument is returned unchanged. The wide version, towupper , should normally be used instead.
The toupper function converts a lower-case letter to the corresponding
upper-case letter.
For single character representations,
the value of the argument is
representable as an unsigned char
or the value of EOF .
The functionality of this API is independent of the program's current locale.
Examples:
@code
#include<ctype.h> //toupper()
#include<stdio.h> //printf()
int test_toupper()
{
struct st
{
int input;
int output;
};
struct st arr[]=
{
{ 'q', 'Q' },
{ 'G' , 'G' },
{ '9' , '9' },
{ '%' , '%' },
{ ' ' , ' ' },
};
int i = 0;
int size = 5;
for( i=0; i<size; i++)
{
int ret = toupper(arr[i].input);//call to the API with the chars in arr[]
if( ret != arr[i].output )
{
printf("
%c cannot convert ", arr[i].input);
}
else
{
printf("
%c ", arr[i].output);
}
}
printf("
");
}
@endcode
Output
@code
q
G
9
%
@endcode
@see isupper()
@see towupper()
@see defns()
@publishedAll
@externallyDefinedApi
*/
/** @def _tolower(c)
This macro always expect that the argument sent is always in uppercase and works only with c locale.
else the behavior is undefined
@publishedAll
@released
*/
/** @def _toupper(c)
This macro always expect that the argument sent is always in lowercase and works only with c locale.
else the behavior is undefined
@publishedAll
@released
*/
/** @def isascii(c)
Checks if ascii.
@publishedAll
@released
*/
/** @def toascii(c)
Converts to ascii.
@publishedAll
@released
*/