Thread: scanf and whitespaces

Hi,

I know this is a common topic on this forum, but I haven't found a nice, clean solution anywhere. Main thing is that I'm never sure whether the solution described really applies to my code. And when I try to integrate pieces of code from those solutions in my own code it never does what I want it to .

I request some inputs from the user:

Code:

puts("\n--------------------------------");
    puts("Please enter the vehicle make: ");
    scanf("%s", &vehicle_make);
    puts("Please enter the vehicle model: ");
    scanf("%s", &vehicle_model);
    puts("Please enter the model year:");
    scanf("%s", &vehicle_year);
    puts("Please enter your name:");
    scanf("%s", &tester);
    puts("--------------------------------");

Now when I have for example a 205 GTI and enter that after Please enter the vehicle model it skips Please enter the model year. I found out that it is because of the space between 205 and GTI, because GTI is stored as vehicle_year if I enter the string above.

Has anyone got a solution for this problem? I know it's probably quite simple, but not for me (yet) .

Thanks very much in advance!

René

Hehe, just kidding...

I hope it's as easy as you say but I'm off work now. I'll try this tomorrow morning first thing. Thanks!

Just make sure you don't forget that, in this case, if you type less than 29 characters, fgets() will also read a \n into the buffer and this might cause you trouble if you're going to compare the string read with a constant like "quit".

Can't you also use getchar() after a scanf() to flush the buffer and avoid that error?

Originally Posted by qqqqxxxx

Code:

vehicle_make[strlen(vehicle_make)-1]='\0' ;

just use this after the assignment , this clears the '\n' at the end of vehicle_make array.

Simple and effective, what more do you want?

Thanks a lot, appreciate your help guys!

Is there an easy way to fill up the fgets() string up to 29 characters? Or just simply to delete the '\n' at the end? I write this data to an exernal text file where formatting is important as well, so it would be nicer if I don't have that \n at the end.

I usually do this:

Code:

#include <string.h>
void cleanup(char *s)
{
    char *p;
    int c;

    if ((p = strchr(s, '\n')) != NULL)
        *p = '\0';
    else
        while ((c = getchar()) != EOF && c != '\n')
            ;
}

If fgets read everything that was to read from the input buffer, a \n will be found on s, otherwise the input buffer will still have the \n and problably more characters so the else takes care of that.

Sorry I was thinking about using a getchar() by itself before a getchar assignment if characters are to be entered after the scanf():

Code:

                                                scanf("%d" , &num);
                                                getchar();
                                                x = getchar();

Code:

if(vehicle_make[strlen(vehicle_make)-1]=='\n')
 vehicle_make[strlen(vehicle_make)-1]='\0';

this should do the trick?