C Programming/ctype.h/Function reference

Description
This function tests whether the character c is of class alpha or digit in the current locale.

Description
This function tests whether the character c is alphabetic in the current locale.

Description
This function tests whether the character c is a space or a tab in the current locale.

Description
This function returns true if c is a control character (that is, a character that is not a printing character).

Description
This function returns true if c is a decimal digit ('0' through '9').

Description
This function returns true if c is a character that has a glyph associated with it. Whitespace characters are not considered graphic.

Description
This function tests whether the character c is lowercase.

Description
This function returns true if c is a printing character. Printing characters include all the graphic characters, plus the space character.

Description
This function returns true if c is a punctuation character. This includes any printing character that is not alphanumeric or a space character.

Description
Returns true if c is a whitespace character. In the standard C locale, these are the valid space characters:
 * Spaces
 * Horizontal tabs
 * Vertical tabs
 * Newlines
 * Formfeeds
 * Carriage returns

Description
This function tests whether the character c is uppercase.

Description
This function tests whether the character c is a hexadecimal dight ('0' through 'F').

Description
This function transliterates an uppercase character to lowercase and returns it. If c is not an uppercase letter, c is returned unchanged.

Description
This function transliterates a lowercase character to uppercase and returns it. If c is not a lowercase letter, c is returned unchanged.