#include<stdio.h>

void strlwr(char *s);

main()
{
char a[50];
printf("Enter a string\n");
gets(a);
strlwr(a);
printf("The Converted string is\n");
puts(a);
}

void strlwr(char *s)
{

while(*s!='\0')
{
if(*s>=97&&*s<=122)
{ *s=*s-32;

}
s++;
}

}
     
           
Note: Need to be arranged in compiler after copied
   

 OutPut:

Enter a string Upper String The Converted string is UPPER STRING