(SOLVED) New to C, having a problem

unilx · 2011-07-21 01:49:04

I'm new to c and I'm having a slight problem.I'm doing an exercise and wrote a simple program, it compiles fine but when i run the program and input my first & last names only my last name and the space are being displayed to the terminal.

// A program that asks two questions, first name & last name then concatenate the strings together

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

main ()
{
            
        // Define your variables
            
        char           fname[43];
        char           lname[20];
        char           space[2];
        int            length;
            
        // This will read in your variables. ( Initializing it ) 

        printf ("Enter your first name: ");
        scanf ("%s", fname);          
                
        setbuf (stdin, NULL);
            
        // This will read in your variables. ( Initializing it ) 

        printf ("Enter your last name: ");
        scanf ("%s", fname);

        
            
        // Initialize the space variable, concatenate the variables together & find the size of the name.
            
        strcpy (space, " ");
            
        strcat (fname, space);
        strcat (fname, lname);
        length = strlen (fname);

        printf ("\n");
            
        printf ("Your name is %s & the size of your name is %d bytes\n", fname, length);
            



        // This will stop the program from exiting until one byte of data is entered. ( A keystroke )

            
        setbuf (stdin, NULL);
        getchar();
}

Last edited by unilx (2011-07-21 02:13:31)

karol · 2011-07-21 02:03:14

I don't know anything about C, but I think you have a typo:

        printf ("Enter your last name: ");
        scanf ("%s", fname);

Shouldn't it be 'lname'?
I've compiled it with this change and it seems to work (although you might want to subtract the space from the count):

[karol@black test]$ ./t1
Enter your first name: karol
Enter your last name: bla

Your name is karol bla & the size of your name is 9 bytes

Last edited by karol (2011-07-21 02:05:34)

unilx · 2011-07-21 02:13:03

I don't know how i missed that...damn typos.
Thanks for the help.

Stebalien · 2011-07-21 06:05:17

Just be careful of buffer overflows. Here is a better input method:

void get_input(char *buffer, int length) {
    char *nl;
    fgets (buffer, length, stdin);
    if ((nl = strchr(buffer, '\n')) != NULL) {
        *nl = '\0';
    }
}

Arch Linux

#1 2011-07-21 01:49:04

(SOLVED) New to C, having a problem

#2 2011-07-21 02:03:14

Re: (SOLVED) New to C, having a problem

#3 2011-07-21 02:13:03

Re: (SOLVED) New to C, having a problem

#4 2011-07-21 06:05:17

Re: (SOLVED) New to C, having a problem

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