Click this button to go to the index for this section.

flockfile(3)
NAME
  flockfile - Locks a stdio stream

LIBRARY
  Standard C Library (libc.a)

SYNOPSIS
  #include <stdio.h>
  void flockfile(
      FILE * file );

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  flockfile,   POSIX.1c

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  file Specifies the stream to be locked.

DESCRIPTION
  The flockfile() function locks a stdio stream so that a thread can have
  exclusive use of that stream for multiple I/O operations.  Use the
  flockfile() function for a thread that wishes to ensure that the output of
  several printf() functions, for example, is not garbled by another thread
  also trying to use printf().

  Matching flockfile() and funlockfile() calls can be nested.

  The behavior of the flockfile() function is unspecified if the file
  parameter does not point to a valid FILE structure.

RELATED INFORMATION
  Functions: funlockfile(3), getc_unlocked(3), putc_unlocked(3)