toupper
Header: <ctype.h>
Converts the given character to uppercase according to the character conversion rules defined by the currently installed C locale.
# Declarations
int toupper( int ch );
# Parameters
ch: character to be converted. If the value of ch is not representable as unsigned char and does not equal EOF, the behavior is undefined.
# Return value
Uppercase version of ch or unmodified ch if no uppercase version is listed in the current C locale.
# Example
#include <ctype.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
int main(void)
{
// in the default locale:
for (unsigned char l = 0, u; l != UCHAR_MAX; ++l)
if ((u = toupper(l)) != l)
printf("%c%c ", l, u);
printf("\n\n");
unsigned char c = '\xb8'; // the character ž in ISO-8859-15
// but ¸ (cedilla) in ISO-8859-1
setlocale(LC_ALL, "en_US.iso88591");
printf("in iso8859-1, toupper('0x%x') gives 0x%x\n", c, toupper(c));
setlocale(LC_ALL, "en_US.iso885915");
printf("in iso8859-15, toupper('0x%x') gives 0x%x\n", c, toupper(c));
}