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/*
* Copyright (c) 2003 Gunnar Ritter
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute
* it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*/
/* Sccsid @(#)iblok.h 1.5 (gritter) 7/16/04 */
/*
* Functions to read a file sequentially.
*/
#include <sys/types.h> /* for off_t, pid_t */
#include <stdio.h> /* for EOF */
#include <wchar.h> /* for wchar_t */
#include <limits.h> /* for MB_LEN_MAX */
struct iblok {
long long ib_endoff; /* offset of endc from start of file */
char ib_mbuf[MB_LEN_MAX+1]; /* multibyte overflow buffer */
char *ib_mcur; /* next byte to read in ib_mbuf */
char *ib_mend; /* one beyond last byte in ib_mbuf */
char *ib_blk; /* buffered data */
char *ib_cur; /* next character in ib_blk */
char *ib_end; /* one beyond last byte in ib_blk */
int ib_fd; /* input file descriptor */
int ib_errno; /* errno on error, or 0 */
int ib_incompl; /* had an incomplete last line */
int ib_mb_cur_max; /* MB_CUR_MAX at time of ib_alloc() */
int ib_seekable; /* had a successful lseek() */
pid_t ib_pid; /* child from ib_popen() */
unsigned ib_blksize; /* buffer size */
};
/*
* Allocate an input buffer with file descriptor fd. blksize may be
* either the size of a buffer to allocate in ib_blk, or 0 if the
* size is determined automatically. On error, NULL is returned and
* errno indicates the offending error.
*/
extern struct iblok *ib_alloc(int fd, unsigned blksize);
/*
* Deallocate the passed input buffer. The file descriptor is not
* closed.
*/
extern void ib_free(struct iblok *ip);
/*
* Open file name and do ib_alloc() on the descriptor.
*/
extern struct iblok *ib_open(const char *name, unsigned blksize);
/*
* Close the file descriptor in ip and do ib_free(). Return value is
* the result of close().
*/
extern int ib_close(struct iblok *ip);
/*
* A workalike of popen(cmd, "r") using iblok facilities.
*/
extern struct iblok *ib_popen(const char *cmd, unsigned blksize);
/*
* Close an iblok opened with ib_popen().
*/
extern int ib_pclose(struct iblok *ip);
/*
* Read new input buffer. Returns the next character (or EOF) and advances
* ib_cur by one above the bottom of the buffer.
*/
extern int ib_read(struct iblok *ip);
/*
* Get next character. Return EOF at end-of-file or read error.
*/
#define ib_get(ip) ((ip)->ib_cur < (ip)->ib_end ? *(ip)->ib_cur++ & 0377 :\
ib_read(ip))
/*
* Unget a character. Note that this implementation alters the read buffer.
* Caution: Calling this macro more than once might underflow ib_blk.
*/
#define ib_unget(c, ip) (*(--(ip)->ib_cur) = (char)(c))
/*
* Get file offset of last read character.
*/
#define ib_offs(ip) ((ip)->ib_endoff - ((ip)->ib_end - (ip)->ib_cur - 1))
/*
* Read a wide character using ib_get() facilities. *wc is used to store
* the wide character, or WEOF if an invalid byte sequence was found.
* The number of bytes consumed is stored in *len. Return value is the
* corresponding byte sequence, or NULL at end-of-file in input.
*
* Note that it is not possible to mix calls to ib_getw() with calls to
* ib_get(), ib_unget() or ib_seek() unless the last character read by
* ib_getw() was L'\n'.
*/
extern char *ib_getw(struct iblok *ip, wint_t *wc, int *len);
/*
* Get a line from ip, returning the line length. Further arguments are either
* the pointer to a malloc()ed buffer and a pointer to its size, or (NULL, 0)
* if ib_getlin() shall allocate the buffer itselves. ib_getlin() will use
* the realloc-style function reallc() to increase the buffer if necessary;
* this function is expected never to fail (i. e., it must longjmp() or abort
* if it cannot allocate a buffer of the demanded size).
* On end-of-file or error, 0 is returned.
*/
extern size_t ib_getlin(struct iblok *ip, char **line, size_t *alcd,
void *(*reallc)(void *, size_t));
/*
* Like lseek().
*/
extern off_t ib_seek(struct iblok *ip, off_t off, int whence);
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