fclose – Close a Stream

fclose is a frequently used C standard library which closes the file associated with the stream and disassociates it.


fclose – close a stream


#include <stdio.h>
int fclose(FILE *fp);


The fclose() function will flushes the stream pointed to by fp (writing any buffered output data using fflush()) and closes the underlying file descriptor.


Upon successful completion 0 is returned.  Otherwise, EOF is returned and errno is set to indicate the error.  In either  case any further access (including another call to fclose()) to the stream results in undefined behaviour.


EBADF  The file descriptor underlying fp is not valid.

The fclose() function may also fail and set errno for any of the errors  specified  for  the  routines  close(),
write() or fflush().


C89, C99.


Note  that  fclose()  only  flushes the user space buffers provided by the C library.  To ensure that the data is physically stored on disk the kernel buffers must be flushed too, for example, with sync() or fsync().

From Linux Programmer’s Manual


#include <stdio.h>
int main(int argc, char* args[])
  FILE * fp;
  pFile = fopen ("file_to_write.txt","wt");
  fprintf (fp, "fclose example");
  fclose (fp);
  return 0;

Eric Ma

Eric is a systems guy. Eric is interested in building high-performance and scalable distributed systems and related technologies. The views or opinions expressed here are solely Eric's own and do not necessarily represent those of any third parties.

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