DragonFly On-Line Manual Pages

ISDIGIT(3)	      DragonFly Library Functions Manual	    ISDIGIT(3)


isdigit, isdigit_l, isnumber, isnumber_l -- decimal-digit character test


Standard C Library (libc, -lc)


#include <ctype.h> int isdigit(int c); int isnumber(int c); int isdigit_l(int c, locale_t locale); #include <xlocale.h> int isnumber_l(int c, locale_t locale);


The isdigit() and isdigit_l() functions test for a decimal digit charac- ter. Regardless of locale, this includes the following characters only: ``0'' ``1'' ``2'' ``3'' ``4'' ``5'' ``6'' ``7'' ``8'' ``9'' The isnumber() and isnumber_l() functions behave similarly to isdigit() and isdigit_l(), but may recognize additional characters, depending on the current locale setting. The value of the argument must be representable as an unsigned char or the value of EOF. The _l-suffixed versions take an explicit locale argument, whereas the non-suffixed versions use the current global or per-thread locale.


The isdigit(), isdigit_l(), isnumber(), and isnumber_l() functions return zero if the character tests false and return non-zero if the character tests true.


The 4.4BSD extension of accepting arguments outside of the range of the unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The iswdigit(), iswdigit_l(), iswnumber(), and iswnumber_l() functions should be used instead.


ctype(3), ctype_l(3), iswdigit(3), iswdigit_l(3), multibyte(3), xlocale(3), ascii(7)


The isdigit() function conforms to ISO/IEC 9899:1990 (``ISO C90''). The isdigit_l() function conforms to IEEE Std 1003.1-2008 (``POSIX.1'').


The isnumber() function appeared in 4.4BSD. DragonFly 4.3 December 25, 2013 DragonFly 4.3