SHELL UNIX-LINUX PROGRAM TO CONVERT LOWER CASE TO UPPER CASE

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

void main()
{
    char sentence[100];
    int count, ch, i;

    printf("Enter a sentence \n");
    for (i = 0; (sentence[i] = getchar()) != '\n'; i++)
    {
        ;
    }
    sentence[i] = '\0';
    /*  shows the number of chars accepted in a sentence */
    count = i;
    printf("The given sentence is   : %s", sentence);
    printf("\n Case changed sentence is: ");
    for (i = 0; i < count; i++)
    {
        ch = islower(sentence[i])? toupper(sentence[i]) :
tolower(sentence[i]);
        putchar(ch);
    }
} 




Output:

[csuser@localhost ~]$ gcc l.c
[csuser@localhost ~]$ ./a.out
Enter a sentence
kishan
The given sentence is   : kishan
 Case changed sentence is: KISHAN