#ifndef WH_UTIL_H_3431399a_
#define WH_UTIL_H_3431399a_

#include <stdio.h>

/*
 * util_memopen_w(char **sp, int *lp) opens a FILE * which accumulates
 *  everything written to it.  Once the stream is closed, *sp is set to
 *  point to the accumulated data; *lp is set to its length.  sp and/or
 *  lp may be nil, in which case that is not returned.  No terminating
 *  NUL is implicit.  After the open and before the close, *sp and *lp
 *  (when sp resp. lp non-nil) are unspecified, may point to anything
 *  or nothing, and may be modified at any moment.  If sp is non-nil,
 *  the final value of *sp is memory suitable for handing directly to
 *  free().
 */
extern FILE *util_memopen_w(char **, int *);

/*
 * util_memopen_r opens a block of memory for reading.  The returned
 *  FILE * reads from the block of memory, showing EOF once the end of
 *  the block is reached.
 */
extern FILE *util_memopen_r(const char *, int);

/*
 * util_teeopen_r(rf,tf,flags) returns a FILE * that, when read from,
 *  reads from rf and returns the data read, but, as a side effect, a
 *  copy of everything read is written to tf.  (Because of buffering,
 *  tf may receive data that hasn't yet been returned by the tee
 *  streem.)
 *
 * flags contains flag bits:
 *
 *	TEE_F_CLOSE_R
 *		If this flag bit is set, closing the returned stream
 *		automatically closes rf.  By default, rf is left
 *		untouched when the tee streem is closed.
 *	TEE_F_CLOSE_TEE
 *		If this flag bit is set, closing the returned stream
 *		automatically closes tf.  By default, tf is left
 *		untouched when the tee streem is closed.
 *
 * util_teeopen_r returns nil if it finds an unrecognized bit set in
 *  flags.
 */
extern FILE *util_teeopen_r(FILE *, FILE *, unsigned int);
#define TEE_F_CLOSE_R   0x00000001
#define TEE_F_CLOSE_TEE 0x00000002

/*
 * util_teeopen_w(fa,fb,flags) returns a FILE * that, when written to,
 *  writes the data to both fa and fb.  (Because of buffering, these
 *  writes may be delayed.)
 *
 * flags contains flag bits:
 *
 *	TEE_F_CLOSE_A
 *		If this flag bit is set, closing the returned stream
 *		automatically closes fa.  By default, fa is left
 *		untouched when the tee streem is closed.
 *	TEE_F_CLOSE_B
 *		If this flag bit is set, closing the returned stream
 *		automatically closes fb.  By default, fb is left
 *		untouched when the tee streem is closed.
 *
 * util_teeopen_w returns nil if it finds an unrecognized bit set in
 *  flags.
 */
extern FILE *util_teeopen_w(FILE *, FILE *, unsigned int);
#define TEE_F_CLOSE_A 0x00000001
#define TEE_F_CLOSE_B 0x00000002

#endif