HPUX setbuf[3s]

 setbuf(3S)                                                       setbuf(3S)





 NAME
      setbuf(), setvbuf() - assign buffering to a stream file

 SYNOPSIS
      #include <stdio.h>

      void setbuf(FILE *stream, char *buf);

      int setvbuf(FILE *stream, char *buf, int type, size_t size);

 DESCRIPTION
      setbuf() can be used after a stream has been opened but before it is
      read or written.  It causes the array pointed to by buf to be used
      instead of an automatically allocated buffer.  If buf is the NULL
      pointer input/output will be completely unbuffered.

      A constant BUFSIZ, defined in the <stdio.h> header file, tells how big
      an array is needed:

           char buf[BUFSIZ];

      setvbuf() can be used after a stream has been opened but before it is
      read or written.  type determines how stream is to be buffered.  Legal
      values for type (defined in <stdio.h>) are:

           _IOFBF      causes input/output to be fully buffered.

           _IOLBF      causes output to be line buffered; the buffer will be
                       flushed when a newline is written, the buffer is
                       full, or input is requested.

           _IONBF      causes input/output to be completely unbuffered.

      When an output stream is unbuffered, information is queued for writing
      on the destination file or terminal as soon as written; when it is
      buffered, many characters are saved up and written as a block.  When
      the output stream is line-buffered, each line of output is queued for
      writing on the destination terminal as soon as the line is completed
      (that is, as soon as a new-line character is written or terminal input
      is requested).  fflush() can also be used to explicitly write the
      buffer.

      If buf is not the NULL pointer, the array it points to is used for
      buffering instead of an automatically allocated buffer (from
      malloc()).  size specifies the size of the buffer to be used.  The
      constant BUFSIZ in <stdio.h> is suggested as a good buffer size.  If
      input/output is unbuffered, buf and size are ignored.

      By default, output to a terminal is line buffered and all other
      input/output is fully buffered.




 Hewlett-Packard Company            - 1 -     HP-UX Release 9.0: August 1992






 setbuf(3S)                                                       setbuf(3S)





 SEE ALSO
      fopen(3S), getc(3S), malloc(3C), putc(3S), stdio(3S).

 DIAGNOSTICS
      If an illegal value for type or size is provided, setvbuf() returns a
      non-zero value.  Otherwise, the value returned will be zero.

 NOTE
      A common source of error is allocating buffer space as an
      ``automatic'' variable in a code block, then failing to close the
      stream in the same block.

 STANDARDS CONFORMANCE
      setbuf(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

      setvbuf(): AES, SVID2, XPG2, XPG3, XPG4, ANSI C






































 Hewlett-Packard Company            - 2 -     HP-UX Release 9.0: August 1992