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C ferror() function

C library function - ferror()

The ferror() function check for an error in reading from or writing to the given stream.When an error occurs, the error indicator remains set until you close stream, call the clearerr() function.

Syntax:

int ferror(FILE *stream)

ferror() Parameters:

Name Description Required /Optional
stream Identifies an address for a file descriptor, which is an area of memory associated with an input or output stream. Required

Return value from ferror()

  • The ferror() function shall return non-zero if and only if the error indicator is set for stream.

Example: ferror() function

Following example puts data out to a stream, and then checks that a write error (invalid filename) has not occurred.

#include <stdio.h>
 
int main(void)
{
   FILE *stream;
   char *string = "C programming.";
   stream = fopen("*test.txt","w");
 
   fprintf(stream, "%s\n", string);
   if (ferror(stream))
   {
      printf("write error\n");
      clearerr(stream);
   }
   if (fclose(stream))
      perror("fclose error");
}

Output:

fclose error: Invalid argument

C Programming Code Editor:

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C Programming: Tips of the Day

What's an object file in C?

An object file is the real output from the compilation phase. It's mostly machine code, but has info that allows a linker to see what symbols are in it as well as symbols it requires in order to work. (For reference, "symbols" are basically names of global objects, functions, etc.)

A linker takes all these object files and combines them to form one executable (assuming that it can, i.e.: that there aren't any duplicate or undefined symbols). A lot of compilers will do this for you (read: they run the linker on their own) if you don't tell them to "just compile" using command-line options. (-c is a common "just compile; don't link" option.)

Ref : https://bit.ly/3CbzF8M