man3/fpurge.3

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  25 .TH FPURGE 3  2017-09-15 "" "Linux Programmer's Manual"
  26 .SH NAME
  27 fpurge, __fpurge \- purge a stream
  28 .SH SYNOPSIS
  29 .nf
  30 /* unsupported */
  31 .B #include <stdio.h>
  32 .PP
  33 .BI "int fpurge(FILE *" stream );
  34 .PP
  35 /* supported */
  36 .B #include <stdio.h>
  37 .B #include <stdio_ext.h>
  38 .PP
  39 .BI "void  __fpurge(FILE *" stream );
  40 .fi
  41 .SH DESCRIPTION
  42 The function
  43 .BR fpurge ()
  44 clears the buffers of the given stream.
  45 For output streams this discards any unwritten output.
  46 For input streams this discards any input read from the underlying object
  47 but not yet obtained via
  48 .BR getc (3);
  49 this includes any text pushed back via
  50 .BR ungetc (3).
  51 See also
  52 .BR fflush (3).
  53 .PP
  54 The function
  55 .BR __fpurge ()
  56 does precisely the same, but without returning a value.
  57 .SH RETURN VALUE
  58 Upon successful completion
  59 .BR fpurge ()
  60 returns 0.
  61 On error, it returns \-1 and sets
  62 .I errno
  63 to indicate the error.
  64 .SH ERRORS
  65 .TP
  66 .B EBADF
  67 .I stream
  68 is not an open stream.
  69 .SH ATTRIBUTES
  70 For an explanation of the terms used in this section, see
  71 .BR attributes (7).
  72 .ad l
  73 .nh
  74 .TS
  75 allbox;
  76 lbx lb lb
  77 l l l.
  78 Interface       Attribute       Value
  79 T{
  80 .BR __fpurge ()
  81 T}      Thread safety   MT-Safe race:stream
  82 .TE
  83 .hy
  84 .ad
  85 .sp 1
  86 .SH CONFORMING TO
  87 These functions are nonstandard and not portable.
  88 The function
  89 .BR fpurge ()
  90 was introduced in 4.4BSD and is not available under Linux.
  91 The function
  92 .BR __fpurge ()
  93 was introduced in Solaris, and is present in glibc 2.1.95 and later.
  94 .SH NOTES
  95 Usually it is a mistake to want to discard input buffers.
  96 .SH SEE ALSO
  97 .\" .BR fclean (3),
  98 .BR fflush (3),
  99 .BR setbuf (3),
 100 .BR stdio_ext (3)