020n_toupper.asciidoc

toupper

NAME

tolower - convert a character to its upper-case pendant.

SYNOPSIS

#include <ctype.h>

#define _toupper(c) ((c) - 'a' + 'A')

int toupper   (int c);
int toupper_l (int c, locale_t locale);

DESCRIPTION

Converts the given character to uppercase according to the character conversion rules defined by the currently installed C locale.

In the default "C" locale, the following lowercase letters abcdefghijklmnopqrstuvwxyz are replaced with respective uppercase letters ABCDEFGHIJKLMNOPQRSTUVWXYZ.

The above _toupper macro is a simpler version of toupper that can be used when c is known to be a lowercase character.

RETURN VALUE

Uppercase version of c or unmodified ch if no uppercase version is listed in the current C locale.

SEE ALSO

tolower

Note

The details of what constitutes an uppercase or lowercase letter depend on the current locale. For example, the default "C" locale does not know about "umlauts", so no conversion is done for them. In some non - English locales, there are lowercase letters with no corresponding uppercase equivalent; the German "sharp s" is one example.

EXAMPLE

link:src/toupper1.c[role=include]

OUTPUT

$ gcc -Wall toupper1.c
$ ./a.out
toupper(_) = _
toupper(`) = `
toupper(a) = A
toupper(b) = B

EXAMPLE

link:src/toupper2.c[role=include]

OUTPUT

$ gcc -Wall toupper2.c
$ ./a.out
aA

EXAMPLE

link:src/toupper3.c[role=include]

OUTPUT

$ gcc -Wall toupper3.c
$ ./a.out
aA bB cC dD eE fF gG hH iI jJ kK lL mM nN oO pP qQ rR sS tT uU vV wW xX yY zZ

in iso8859-1, toupper('0xb8') gives 0xb8
in iso8859-15, toupper('0xb8') gives 0xb4