SAS/C Library Reference, Vol. 1

toupper -- Translate Lowercase Character to Uppercase

SYNOPSIS

 #include <ctype.h>

 int toupper(int c);

DESCRIPTION

toupper translates a lowercase character c to the corresponding uppercase character. The argument must either be a char value or EOF. The mapping of lowercase to uppercase characters is locale dependent.

RETURN VALUE

If the argument is a lowercase character, the corresponding uppercase character is returned; otherwise, the argument value is returned.

IMPLEMENTATION

toupper is implemented by the compiler as a built-in function, unless you use the name toupper with #undef.

EXAMPLE

  #include <ctype.h>
  #include <stdio.h>

  #define MAX 40

  main()
  {
     char *str, *ptr;
     char input[MAX];

     puts("Enter a string of lowercase characters (maximum of 40):");
     str = gets(input);

     ptr = str;

        /* Translate all lowercase characters in a string to      */
        /*  uppercase characters.                                 */
     while (*str) {
        *str = toupper(*str);

           /* Increment outside of macro for maximum portability. */
        str++;
     }
     printf("%sn", ptr);
  }

RELATED FUNCTIONS

isupper, memupr, strupr, tolower