buffer(3) Library Functions Manual buffer(3)NAME
buffer.h - generic read/write buffering
SYNTAX
#include <buffer.h>
buffer* buffer_0; /* like stdio's stdin */
buffer* buffer_1; /* like stdio's stdout */
buffer* buffer_2; /* like stdio's stderr */
DESCRIPTION
buffer.h provides a generic buffer interface that can be used for read and write buffering. Buffers must be initialized with buffer_init.
A buffer can only be used for reading or writing at the same time, not both.
Unlike stdio, these write buffers are not flushed automatically at program termination; you must manually call buffer_flush, buf-
fer_putsflush, buffer_putflush or buffer_putnlflush.
EXAMPLE
See buffer_init(3) for example read buffer code. Here is typical code for printing an error message on stderr:
#include <buffer.h>
buffer_puts(buffer_2,"error: got only ");
buffer_putulong(buffer_2,got);
buffer_puts(buffer_2," bytes, but expected at least ");
buffer_putulong(buffer_2,expected);
buffer_putsflush(buffer_2," bytes!");
SEE ALSO buffer_init(3), buffer_put(3), buffer_get(3), buffer_flush(3)buffer(3)
Check Out this Related Man Page
setbuf(3C) Standard C Library Functions setbuf(3C)NAME
setbuf, setvbuf - assign buffering to a stream
SYNOPSIS
#include <stdio.h>
void setbuf(FILE *stream, char *buf);
int setvbuf(FILE *stream, char *buf, int type, size_t size);
DESCRIPTION
The setbuf() function may be used after the stream pointed to by stream (see intro(3)) is 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. The constant BUFSIZ, defined in the <stdio.h> header, indicates the size of the array pointed to by buf.
The setvbuf() function may be used after a stream is opened but before it is read or written. The type argument determines how stream
will be buffered. Legal values for type (defined in <stdio.h>) are:
_IOFBF Input/output to be fully buffered.
_IOLBF Output to be line buffered; the buffer will be flushed when a NEWLINE is written, the buffer is full, or input is
requested.
_IONBF Input/output to be completely unbuffered.
If buf is not the null pointer, the array it points to will be used for buffering, instead of an automatically allocated buffer. The size
argument specifies the size of the buffer to be used. If input/output is unbuffered, buf and size are ignored.
For a further discussion of buffering, see stdio(3C).
RETURN VALUES
If an illegal value for type is provided, setvbuf() returns a non-zero value. Otherwise, it returns 0.
USAGE
A common source of error is allocating buffer space as an "automatic" variable in a code block, and then failing to close the stream in the
same block.
When using setbuf(), buf should always be sized using BUFSIZ. If the array pointed to by buf is larger than BUFSIZ, a portion of buf will
not be used. If buf is smaller than BUFSIZ, other memory may be unexpectedly overwritten.
Parts of buf will be used for internal bookkeeping of the stream and, therefore, buf will contain less than size bytes when full. It is
recommended that stdio(3C) be used to handle buffer allocation when using setvbuf().
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO fopen(3C), getc(3C), malloc(3C), putc(3C), stdio(3C), attributes(5), standards(5)SunOS 5.10 14 Aug 2002 setbuf(3C)