tolower -- Translate Uppercase Character to Lowercase


SYNOPSIS
#include <ctype.h>
int tolower(int c);
DESCRIPTION
tolower
translates an uppercase character to the corresponding
lowercase character. The argument must either be a char
value or
EOF
. The mapping of uppercase to lowercase characters is
locale dependent.
RETURN VALUE
If the argument is an uppercase character, the corresponding lowercase
character is returned; otherwise, the argument value is returned.
IMPLEMENTATION
tolower
is implemented by the compiler as a built-in function, unless
you use the name tolower
with #undef
.
EXAMPLE
#include <ctype.h>
#include <stdio.h>
#define MAX 40
main()
{
char *str, *ptr;
char input[MAX];
puts("Enter a string of uppercase characters (maximum of 40):");
str = gets(input);
ptr = str;
/* Translate all uppercase characters in a string to */
/* lowercase characters. */
while (*str) {
*str = tolower(*str);
/* Increment outside of macro for maximum portability. */
str++;
}
printf("%sn", ptr);
}
RELATED FUNCTIONS
islower
, memlwr
, strlwr
, toupper
SEE ALSO