CTYPE(3) | NetBSD Library Functions Manual | CTYPE(3) |
isalpha(int c);
isupper(int c);
islower(int c);
isdigit(int c);
isxdigit(int c);
isalnum(int c);
isspace(int c);
ispunct(int c);
isprint(int c);
isgraph(int c);
iscntrl(int c);
isblank(int c);
toupper(int c);
tolower(int c);
See the specific manual pages for information about the test or conversion performed by each function.
const char *s = "xyz"; while (*s != '\0') { putchar(toupper((int)(unsigned char)*s)); s++; }
Values of type int that were returned by getc(3), fgetc(3), and similar functions or macros are already in the correct range, and may be safely passed to these ctype functions without any casts.
Values of type char or signed char must first be cast to unsigned char, to ensure that the values are within the correct range. The result should then be cast to int to avoid warnings from some compilers. Casting a negative-valued char or signed char directly to int will produce a negative-valued int, which will be outside the range of allowed values (unless it happens to be equal to EOF, but even that would not give the desired result).
May 6, 2010 | NetBSD 5.99 |