setbuffer, setlinebuf

Purpose

     Assigns buffering to a stream.

Library

     Berkeley Library (libbsd.a)

Syntax

     void setbuffer (stream, buf, size)        void setlinebuf (stream)
     FILE *stream;                             FILE *stream;
     char *buf, *size;
     Description

     The setbuffer subroutine, an alternate form of the setbuf
     subroutine described on page  3-397, is used after stream
     has been opened,  but before it is read  or written.  The
     character array buf, whose size is determined by the size
     parameter, is used instead  of an automatically allocated
     buffer.   If  the  buf  parameter  is  a  null  character
     pointer, input/output is completely unbuffered.

     The setbuffer subroutine is  not needed under normal cir-
     cumstances  since the  default file  I/O buffer  size are
     optimal.

     The  setlinebuf subroutine  is used  to change  stdout or
     stderr  from block  buffered or  unbuffered to  line buf-
     fered.  Unlike the setbuf  and setbuffer subroutines, the
     setlinebuf  subroutine  can be  used  any  time the  file
     descriptor is active.

     Note:  Because  the setbuffer and  setlinebuf subroutines
     are  implemented in  AIX using  the setvbuf  system call,
     these routines  may not  function exactly  as they  do in
     4.3BSD.

     For more  information on  stream buffering,  see "setbuf,
     setvbuf."

     Related Information

     In  this  book:    "fclose,  fflush,"   "fopen,  freopen,
     fdopen,"  "fread, fwrite," "getc, fgetc, getchar, getw,"
     "malloc,  free,  realloc,   calloc,"   "printf,  fprintf,
     sprintf, NLprintf, NLfprintf, NLsprintf," "putc, putchar,
     fputc, putw,"  "puts, fputs," and  "setbuf, setvbuf."