CrossWorks for ARM User Guide

DescriptionPortabilityispunct returns nonzero (true) for every printing character for which neither isspacenor isalnum is true.ispunct conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See also isspace (page 246) isalnum (page 244)isspaceSynopsisDescriptionPortability#include int isspace(int c);isspace returns nonzero (true) if and only if the value of the argument c is a standardwhite-space character. The standard white-space characters are space (' '), form feed('\f'), new-line ('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab('\v').isspace conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See also isblank (page 244)isupperSynopsisDescriptionPortability#include int isupper(int c);isupper returns nonzero (true) if and only if the value of the argument c is an uppercaseletter A through Z.isupper conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).isxdigitSynopsisDescriptionPortability#include int isxdigit(int c);isxdigit returns nonzero (true) if and only if the value of the argument c is ahexadecimal digit 0 through 9, a through f, or A through F.isxdigit conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).tolowerSynopsis#include int tolower(int c);246 Chapter 28 Standard C Library Reference