irritating bug wont go

I cant explain why this is happening :

Code:

---

    while(1)
        {
                                                                                                                           
                printf("what do you want to do \n");
                printf("a> Send a file to the backend \n");
                printf("b> Read a file in the backend \n");
                printf("c> Execute a file in the backend \n");
                                                                                                                           
                scanf("%c",&choice);
                printf("choice entered :%c\n",choice);
                 
                printf("enter the name of the file \n");
                ..
.                ...
      }

---

this program is supposed to be in an infinite loop.

After the first loop is completed properly , the three options are displayed and the user is supposed to make his next choice.
But, my program is skipping through the scanf function in the second loop.
The first iteration is as expected,
this is what it shows after the first iteration :

Code:

---

OUPUT:


a> Send a file to the backend
b> Read a file in the backend
c> Execute a file in the backend
choice entered :
 
enter the name of the file

---

Even before i type anything.
in my code, I compare choice to select the option required, it doesnt get changed anywhere.

Why is this happening?

> But, my program is skipping through the scanf function in the second loop.
No, having typed in "a" and "enter", the first scanf("%c") call reads the 'a' and the second one reads the '\n'.

Use fgets to read a whole line of input, then examine that line in memory

phew!! never knew that was happening..
I have a doubt in your method . OK, i will do:

Code:

---

      fgets(&choice,sizeof(char), stdin);

---

fine, what did you mean by check the contents in memory??

in the mean time i had tried this :

Code:

---

  char  *choice;
    while(1)
        {
                choice=malloc(sizeof(char));
                printf("what do you want to do \n");
                printf("a> Send a file to the backend \n");
                printf("b> Read a file in the backend \n");
                printf("c> Execute a file in the backend \n");
                                                                                                                           
                scanf("%c",choice);
                printf("choice entered :%c\n",*choice);
                printf("enter the name of the file \n");
                ..
                ..


                  ..
                  ..
                  free(choice);
        }

---

I thought this would work, but it didnt either..
Can you elaborate your idea a little bit..

Try this:

Code:

---

scanf("%c%*c",&choice);

---

well, that doesnt do the job either

this is the output now :

Code:

---


what do you want to do
a> Send a file to the backend
b> Read a file in the backend
c> Execute a file in the backend
a
choice entered :
 
enter the name of the file

---

Marginally better, as it is waiting for the input from the keyboard, but the choice variable isnt getting updated.

what did you imply anyway??

More spoon feeding

Code:

---

while(1)
{
  char buff[BUFSIZ];
  printf("what do you want to do \n");
  printf("a> Send a file to the backend \n");
  printf("b> Read a file in the backend \n");
  printf("c> Execute a file in the backend \n");
  fgets( buff, BUFSIZ, stdin );
  printf("choice entered :%c\n",buff[0]);
  printf("enter the name of the file \n");
  /* more fgets calls */
}

---

If you just invented a char * variable from looking at the prototype of fgets() and saw a char*, then you need to read the books again.
It is not sufficient to simply declare a bunch of variables with the right type, you have to think about what is going to happen (by reading the manual)

Ofcourse, I know what fgets() does and how it works.
and by the way, your idea still didnt work.
it is still taking in the '\n' as the input to the scanf() , in the second iteration and jumping into the next statement..

Stop mixing your methods of reading input. He didn't say "use fgets then use scanf". He said...

Code:

---

/* more fgets calls */

---

See what happens when you actually pay attention?


Quzah.

oh! sorry, i just typed that carelessly..my fault.

i should have typed "fgets()" instead of "scanf().."

Quote:

---

Originally Posted by nash@nitk

Ofcourse, I know what fgets() does and how it works.
and by the way, your idea still didnt work.
it is still taking in the '\n' as the input to the scanf() , in the second iteration and jumping into the next statement..

---

Then you did it wrong. fgets() can't leave the \n in the buffer for the next fgets() if you used it right -- and Salem used it right. Therefore, you probably didn't.

Maybe you need to post the code that doesn't work....