#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>=65&&*s<=90)
        {   
         *s=*s+32;
        }
        s++;
    }

}
     
           
Note: Need to be arranged in compiler after copied
   

 OutPut:

Enter a string Lower String The Converted string is lower string