question in c?

nesta · 03-29-2007, 04:25 AM

hi all,
i want to make a simple program that reads what i m typing on the keyboard then print it again for me.
here is what i have written:

Code:

#include <stdio.h> 
#include <string.h>

int main ()
{
	char buf[512];
	printf("small test\n");
	printf("if u want to terminate type end\n");
	do
	{
		scanf("%s",buf);
		printf("%s",buf);
	}while(strcmp(buf,"end"));

	
        return 0;
}

when i tried to execute the program by writting:
hello world

i got the following output:
helloworld

it does not sense the space,i want it to print
hello world
as i write exactly.

note that i dont want to use make character by character i.e i dont want to use scanf("%c",buf[i])

thanks in advance

kshkid · 03-29-2007, 04:38 AM

use

fgets and set the stream to STDIN

nesta · 03-29-2007, 04:54 AM

thanks for your help but, now i cant terminate the program.
i want to terminate by writting end
but it does not terminate when i write end
here is my code:

Code:

#include <stdio.h> 
#include <string.h>

int main ()
{
	char buf[512];
	printf("small test\n");
	printf("if u want to terminate type end\n");
	do
	{
		fgets(buf,sizeof(buf),stdin);
		printf("%s\n",buf);

	}while(strcmp(buf,"end"));

        return 0;
}

graemef · 03-29-2007, 04:57 AM

%s uses whitespace as it's break point, which is why the spaces are lost. Why don't you want to use %c?

graemef · 03-29-2007, 05:05 AM

Quote:

Originally Posted by nesta

thanks for your help but, now i cant terminate the program.
i want to terminate by writting end
but it does not terminate when i write end

Because unlike scanf() fgets() doesn't strip any white space (such as the new line)

kshkid · 03-29-2007, 05:32 AM

both of them works,

Code:

#include <stdio.h>
#include <string.h>

int main ()
{
        char buf[512];
        printf("small test\n");
        printf("if u want to terminate type end\n");
        do
        {
                fgets(buf,sizeof(buf),stdin);
                buf[strlen(buf) - 1] = '\0';
                printf("%s\n",buf);
        }while(strcmp(buf,"end"));

        return 0;
}

or this

Code:

#include <stdio.h>
#include <string.h>

int main ()
{
        char buf[512];
        printf("small test\n");
        printf("if u want to terminate type end\n");
        do
        {
                fgets(buf,sizeof(buf),stdin);
                printf("%s",buf);
        }while(strcmp(buf,"end\n"));

        return 0;
}

man fgets
fgets() reads in at most one less than size characters from stream and stores them into the buffer pointed to by s. Reading stops after an EOF or a newline. If a newline is read, it is stored into the buffer.