From 6e376cffb5c86f5d05da2f7e0ecb7fd7f496d017 Mon Sep 17 00:00:00 2001 From: Martin Pieuchot Date: Tue, 1 Jan 2013 17:41:14 +0000 Subject: Add an implementation based on tedu@'s design of fmemopen(3) and open_memstream(3) so they can be polished in-tree. One of the manpages comes from NetBSD with some tweaks. Prodded by espie@, krw@, guenther@ --- lib/libc/stdio/fmemopen.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 lib/libc/stdio/fmemopen.c (limited to 'lib/libc/stdio/fmemopen.c') diff --git a/lib/libc/stdio/fmemopen.c b/lib/libc/stdio/fmemopen.c new file mode 100644 index 00000000000..fd76f625b23 --- /dev/null +++ b/lib/libc/stdio/fmemopen.c @@ -0,0 +1,186 @@ +/* $OpenBSD: fmemopen.c,v 1.1 2013/01/01 17:41:13 mpi Exp $ */ +/* + * Copyright (c) 2011 Martin Pieuchot + * Copyright (c) 2009 Ted Unangst + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include +#include +#include +#include +#include "local.h" + +struct state { + char *string; /* actual stream */ + size_t pos; /* current position */ + size_t size; /* allocated size */ + size_t len; /* length of the data */ +}; + +static int +fmemopen_read(void *v, char *b, int l) +{ + struct state *st = v; + int i; + + for (i = 0; i < l && i + st->pos < st->len; i++) + b[i] = st->string[st->pos + i]; + st->pos += i; + + return (i); +} + +static int +fmemopen_write(void *v, const char *b, int l) +{ + struct state *st = v; + int i; + + for (i = 0; i < l && i + st->pos < st->size; i++) + st->string[st->pos + i] = b[i]; + st->pos += i; + + if (st->pos >= st->len) { + st->len = st->pos; + + if (st->len == st->size) + st->string[st->len - 1] = '\0'; + else + st->string[st->len] = '\0'; + } + + return (i); +} + +static fpos_t +fmemopen_seek(void *v, fpos_t pos, int whence) +{ + struct state *st = v; + + switch (whence) { + case SEEK_SET: + break; + case SEEK_CUR: + pos += st->pos; + break; + case SEEK_END: + /* + * XXX The standard is not clear about where to seek + * from the end of the data or the end of the buffer. + */ + pos += st->len; + break; + default: + errno = EINVAL; + return (-1); + } + + if (pos < 0 || pos > st->size) + return (-1); + + st->pos = pos; + + return (pos); +} + +static int +fmemopen_close(void *v) +{ + free(v); + + return (0); +} + +static int +fmemopen_close_free(void *v) +{ + struct state *st = v; + + free(st->string); + free(st); + + return (0); +} + +FILE * +fmemopen(void *buf, size_t size, const char *mode) +{ + struct state *st; + FILE *fp; + int flags, oflags; + + if (size == 0) { + errno = EINVAL; + return (NULL); + } + + if ((flags = __sflags(mode, &oflags)) == 0) { + errno = EINVAL; + return (NULL); + } + + if (buf == NULL && ((oflags & O_RDWR) == 0)) { + errno = EINVAL; + return (NULL); + } + + if ((st = malloc(sizeof(*st))) == NULL) + return (NULL); + + if ((fp = __sfp()) == NULL) { + free(st); + return (NULL); + } + + st->pos = 0; + st->len = 0; + st->size = size; + + if (buf == NULL) { + if ((st->string = malloc(size)) == NULL) { + free(st); + fp->_flags = 0; + return (NULL); + } + *st->string = '\0'; + } else { + st->string = (char *)buf; + + if ((oflags & O_WRONLY) == 0) + st->len = size; + + if (oflags & O_TRUNC) + *st->string = '\0'; + + if (oflags & O_APPEND) { + char *p; + + if ((p = memchr(st->string, '\0', size)) != NULL) + st->pos = st->len = (p - st->string); + else + st->pos = st->len = size; + } + } + + fp->_flags = (short)flags; + fp->_file = -1; + fp->_cookie = (void *)st; + fp->_read = (flags & __SWR) ? NULL : fmemopen_read; + fp->_write = (flags & __SRD) ? NULL : fmemopen_write; + fp->_seek = fmemopen_seek; + fp->_close = (buf == NULL) ? fmemopen_close_free : fmemopen_close; + + return (fp); +} -- cgit v1.2.3