NAME

boundary_fopen —

read from a stream until a boundary string is matched

LIBRARY

PDEL Library (libpdel, -lpdel)

SYNOPSIS

#include <stdio.h>
#include <pdel/io/boundary_fp.h>

FILE *
boundary_fopen(FILE *fp, const char *boundary, int closeit);

DESCRIPTION

boundary_fopen() creates a new read-only stream that reads data from the underlying stream fp until the boundary string is encountered, after which EOF is returned. If the boundary string does not appear in the underlying stream input, the entire input is passed through unaltered.

When the boundary string appears, the last character readable from the newly created boundary stream will be the character just before the first character of the boundary string. Therefore, the boundary string itself does not appear in the input from the boundary stream. In no case are any characters beyond the last character of the boundary string read out from the underlying stream, i.e., the last character read from the underlying stream will be the last character of the boundary string.

The boundary matching algorithm runs in linear time. However, the boundary string is limited to 255 characters in length (not counting the terminating '\0' byte).

fclose(3) should be used to close the returned stream. The closeit parameter determines whether the underlying stream fp is also closed when the boundary stream is closed.

Boundary streams are useful for online parsing of multipart MIME document body parts as defined in RFC 2046.

RETURN VALUES

boundary_fopen() returns NULL to indicate an error, with errno set appropriately.

HISTORY

The PDEL library was developed at Packet Design, LLC. http://www.packetdesign.com/

AUTHORS

Archie Cobbs ⟨archie@freebsd.org⟩