Switch/Case Fallthrough BUG

[DaemonCoder]

I have a switch/case statement using numerics for a menu, but when i enter an alphanumeric statment it goes into a loop printing my menu and the default statement from switch/case the default statement. The only way to end it is ctrl-c. the code is below. Can someone please explain this quirk to me?

[CODE=c]
#include<stdio. h>
#include<stdlib .h>
int CHOICE;
int LTENC[11];

//SNIPPED - cArrayModify(); / pLastTen();

void doNothing()
{
printf("\n");
cArrayModify();
}

void invalidChoice()
{
printf(" Invalid Choice!! \n");
cArrayModify();
}

void menu()
{
cArrayModify();
printf(" \n \n");
printf(" Menu: \n");
printf(" 1 - Print Menu \n");
printf(" 2 - Do nothing \n");
printf(" 3 - Exit \n \n");
pLastTen();

}

int programexit()
{
printf("\n Exit Conditions met, program will now exit!\n");
return 0;
}

void commandlp()
{
while(1)
{
printf("-> ");
scanf("%d",&CHO ICE);
switch(CHOICE)
{
case 1 : menu();
break;

case 2 : doNothing();
break;

case 3 : programexit();
exit(0);

default: invalidChoice() ;
break;

}
}

}


int main()
{

menu();
commandlp();

}[/CODE]

[oler1s]

Please give an example. Show the program input you used, a bit of sample output, etc.

[gpraghuram]

You are only coming out of switch statement and not the while loop.
The break u have given is only for switch statement.
So you should also exit from while loop or change while to if

Raghuram

[DaemonCoder]

 Menu:
 1 - Print Menu
 2 - Do nothing
 3 - Exit


 Last ten commands: 0, 0, 0, 0, 1, 1, 1, 1, 5,-> s

->  Invalid Choice!!
->  Invalid Choice!!
->  Invalid Choice!!
->  Invalid Choice!!
->  Invalid Choice!!   //  this loops to this with no further user input...

-> ^C

The reason i didnt break oout of the while loop is because this is a menu with an exit function. I dont want it to exit unless the user says to exit.

[oler1s]

Yeah, there's a bug in your code. And it's not the switch statement. I was going to type up a large post, but I realized that an article on scanf explains the issue.

[DaemonCoder]

So using scanf() is my problem... So now i have another issue...

[CODE=C]

<SNIPPED>
while(1)
{
printf("-> ");
sscanf("%*s",CH OICE_STRING);

CHOICE = strcmp (CHOICE_STRING, commandListVari able);
// if commandListVari able == "exit" and CHOICE_STRING == "exit"
// what does this return...???

switch(CHOICE)
{

<snipped>

[/CODE]
Do i have to create a seperate variable for each command or is there a way to use strcmp for a direct comparison to a literal so that i get the correct command executed in the switch statement??

The information that i found says "Returns an integral value indicating the relationship between the strings". How do i 'predict' what the valuse of the comparison will be?