ctype.h

line.gif

isalnum Determines whether a character is alphnumeric.
isalpha Determines whether a character is alphabetic.
iscntrl Determines whether a character is control character.
isdigit Determines whether a character is decimal digit.
isgraph Determines whether a character is a graphics character.
islower Determines whether a character is a lower case alphabetic character.
isprint Determines whether a character is a printable character.
ispunct Determines whether a character is a punctuation character.
isspace Determines whether a character is the space character.
isupper Determines whether a character is an upper case alphabetic character.
isxdigit Determines whether a character is a hexadecimal digit.
tolower Converts upper case alphabetic characters to lower case.
toupper Converts lower case alphabetic characters to upper case.


line.gif