Detecting EOF in C

Question

I am using the following C code to take input from user until EOF occurs, but problem is this code is not working, it terminates after taking first input. Can anyone tell me whats wrong with this code. Thanks in advance.

float input;  printf("Input No: "); scanf("%f", &input);  while(!EOF) {     printf("Output: %f", input);     printf("Input No: ");     scanf("%f", &input); } 

Answer 1

EOF is just a macro with a value (usually -1). You have to test something against EOF, such as the result of a getchar() call.

One way to test for the end of a stream is with the feof function.

if (feof(stdin)) 

Note, that the 'end of stream' state will only be set after a failed read.

In your example you should probably check the return value of scanf and if this indicates that no fields were read, then check for end-of-file.

Answer 2

EOF is a constant in C. You are not checking the actual file for EOF. You need to do something like this

while(!feof(stdin)) 

Here is the documentation to feof. You can also check the return value of scanf. It returns the number of successfully converted items, or EOF if it reaches the end of the file.