| isextalnum | Function (Macro)

ctype.h

short isextalnum (short c);

Checks whether a character is an extended alphanumeric.

isextalnum returns nonzero if c is a symbol which may be used in variable names, including ordinary alphanumerics (see isalnum), underscore ('_') and foreign alphanumerics (see isfrgnalnum), otherwise it returns zero. It is an inline function which is implemented using GNU C smart macros and a library variable. The first call of isextalnum expands to a large code, but any next call of it expands to a relatively small code.