ctype.h File Reference

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Functions
int	isalnum (int c)
	Check if the given character is alphanumeric.
int	isalpha (int c)
	Check if the given character is alphabetic.
int	isascii (int c)
	Check if the given character is a valid ASCII character.
int	isblank (int c)
	Check if the given character is a blank space.
int	iscntrl (int c)
	Check if the given character is a control character.
int	isdigit (int c)
	Check if the given character is a digit.
int	isgraph (int c)
	Check if the given character is printable and not a space.
int	islower (int c)
	Check if the given character is a lowercase alphabetic character.
int	isprint (int c)
	Check if the given character is a printable character (including spaces).
int	ispunct (int c)
	Check if the given character is a punctuation character.
int	isspace (int c)
	Check if the given character is a whitespace character.
int	isupper (int c)
	Check if the given character is an uppercase alphabetic character.
int	isxdigit (int c)
	Check if the given character is a hexadecimal digit.
int	toascii (int c)
	Convert the given character to its ASCII equivalent.
int	tolower (int c)
	Convert the given character to lowercase.
int	toupper (int c)
	Convert the given character to uppercase.

Function Documentation

isalnum()

int isalnum

(

int

c

)

Check if the given character is alphanumeric.

Parameters

c	The character to check.

Returns

Non-zero value if the character is alphanumeric, zero otherwise.

isalpha()

int isalpha

(

int

c

)

Check if the given character is alphabetic.

Parameters

c	The character to check.

Returns

Non-zero value if the character is alphabetic, zero otherwise.

isascii()

int isascii

(

int

c

)

Check if the given character is a valid ASCII character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a valid ASCII character, zero otherwise.

isblank()

int isblank

(

int

c

)

Check if the given character is a blank space.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a blank space, zero otherwise.

iscntrl()

int iscntrl

(

int

c

)

Check if the given character is a control character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a control character, zero otherwise.

isdigit()

int isdigit

(

int

c

)

Check if the given character is a digit.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a digit, zero otherwise.

isgraph()

int isgraph

(

int

c

)

Check if the given character is printable and not a space.

Parameters

c	The character to check.

Returns

Non-zero value if the character is printable and not a space, zero otherwise.

islower()

int islower

(

int

c

)

Check if the given character is a lowercase alphabetic character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a lowercase alphabetic character, zero otherwise.

isprint()

int isprint

(

int

c

)

Check if the given character is a printable character (including spaces).

Parameters

c	The character to check.

Returns

Non-zero value if the character is a printable character, zero otherwise.

ispunct()

int ispunct

(

int

c

)

Check if the given character is a punctuation character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a punctuation character, zero otherwise.

isspace()

int isspace

(

int

c

)

Check if the given character is a whitespace character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a whitespace character, zero otherwise.

isupper()

int isupper

(

int

c

)

Check if the given character is an uppercase alphabetic character.

Parameters

c	The character to check.

Returns

Non-zero value if the character is an uppercase alphabetic character, zero otherwise.

isxdigit()

int isxdigit

(

int

c

)

Check if the given character is a hexadecimal digit.

Parameters

c	The character to check.

Returns

Non-zero value if the character is a hexadecimal digit, zero otherwise.

toascii()

int toascii

(

int

c

)

Convert the given character to its ASCII equivalent.

Parameters

c	The character to convert.

Returns

The ASCII value of the character.

tolower()

int tolower

(

int

c

)

Convert the given character to lowercase.

Parameters

c	The character to convert.

Returns

The lowercase equivalent of the character.

toupper()

int toupper

(

int

c

)

Convert the given character to uppercase.

Parameters

c	The character to convert.

Returns

The uppercase equivalent of the character.