CTYPE(3) Library Functions Manual CTYPE(3)

digittoint, isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, ishexnumber, isideogram, islower, isnumber, isphonogram, isprint, ispunct, isrune, isspace, isspecial, isupper, isxdigit, toascii, tolower, touppercharacter classification macros

Standard C Library (libc, -lc)

#include <ctype.h>

int
digittoint(int c);

int
isalnum(int c);

int
isalpha(int c);

int
isascii(int c);

int
iscntrl(int c);

int
isdigit(int c);

int
isgraph(int c);

int
ishexnumber(int c);

int
isideogram(int c);

int
islower(int c);

int
isnumber(int c);

int
isphonogram(int c);

int
isspecial(int c);

int
isprint(int c);

int
ispunct(int c);

int
isrune(int c);

int
isspace(int c);

int
isupper(int c);

int
isxdigit(int c);

int
toascii(int c);

int
tolower(int c);

int
toupper(int c);

The above functions perform character tests and conversions on the integer c. They are available as macros, defined in the include file <ctype.h>, or as true functions in the C library. See the specific manual pages for more information.

Extended locale versions of these functions are documented in ctype_l(3). See xlocale(3) for more information.

digittoint(3), isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), isideogram(3), islower(3), isphonogram(3), isprint(3), ispunct(3), isrune(3), isspace(3), isspecial(3), isupper(3), isxdigit(3), toascii(3), tolower(3), toupper(3), wctype(3), ascii(7), ctype_l(3)

These functions, except for digittoint(), isascii(), ishexnumber(), isideogram(), isnumber(), isphonogram(), isrune(), isspecial() and toascii(), conform to ISO/IEC 9899:1990 (“ISO C90”).

March 30, 2004 macOS 14.3