diff options
Diffstat (limited to 'mit-pthreads/stdio/fgetline.c')
| -rw-r--r-- | mit-pthreads/stdio/fgetline.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/mit-pthreads/stdio/fgetline.c b/mit-pthreads/stdio/fgetline.c new file mode 100644 index 00000000000..219660612f1 --- /dev/null +++ b/mit-pthreads/stdio/fgetline.c @@ -0,0 +1,170 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * Copyright (c) 1993, 1994 Chris Provenzano. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Chris Torek. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +/*static char *sccsid = "from: @(#)fgetline.c 5.2 (Berkeley) 5/4/91";*/ +static char *rcsid = "$Id$"; +#endif /* LIBC_SCCS and not lint */ + +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "local.h" + +/* + * Expand the line buffer. Return -1 on error. + * The `new size' does not account for a terminating '\0', + * so we add 1 here. + */ +__slbexpand(fp, newsize) + FILE *fp; + size_t newsize; +{ + void *p; + + if (fp->_lb._size >= ++newsize) + return (0); + if ((p = realloc(fp->_lb._base, newsize)) == NULL) + return (-1); + fp->_lb._base = p; + fp->_lb._size = newsize; + return (0); +} + +/* + * Get an input line. The returned pointer often (but not always) + * points into a stdio buffer. Fgetline smashes the newline (if any) + * in the stdio buffer; callers must not use it on streams that + * have `magic' setvbuf() games happening. + */ +char * +fgetline(fp, lenp) + register FILE *fp; + size_t *lenp; +{ + register unsigned char *p; + register size_t len; + size_t off; + + flockfile(fp); + + /* make sure there is input */ + if (fp->_r <= 0 && __srefill(fp)) { + if (lenp != NULL) + *lenp = 0; + funlockfile(fp); + return (NULL); + } + + /* look for a newline in the input */ + if ((p = memchr((void *)fp->_p, '\n', fp->_r)) != NULL) { + register char *ret; + + /* + * Found one. Flag buffer as modified to keep + * fseek from `optimising' a backward seek, since + * the newline is about to be trashed. (We should + * be able to get away with doing this only if + * p is not pointing into an ungetc buffer, since + * fseek discards ungetc data, but this is the + * usual case anyway.) + */ + ret = (char *)fp->_p; + len = p - fp->_p; + fp->_flags |= __SMOD; + *p = 0; + fp->_r -= len + 1; + fp->_p = p + 1; + if (lenp != NULL) + *lenp = len; + funlockfile(fp); + return (ret); + } + + /* + * We have to copy the current buffered data to the line buffer. + * + * OPTIMISTIC is length that we (optimistically) + * expect will accomodate the `rest' of the string, + * on each trip through the loop below. + */ +#define OPTIMISTIC 80 + + for (len = fp->_r, off = 0;; len += fp->_r) { + register size_t diff; + + /* + * Make sure there is room for more bytes. + * Copy data from file buffer to line buffer, + * refill file and look for newline. The + * loop stops only when we find a newline. + */ + if (__slbexpand(fp, len + OPTIMISTIC)) + goto error; + (void) memcpy((void *)(fp->_lb._base + off), (void *)fp->_p, + len - off); + off = len; + if (__srefill(fp)) + break; /* EOF or error: return partial line */ + if ((p = memchr((void *)fp->_p, '\n', fp->_r)) == NULL) + continue; + + /* got it: finish up the line (like code above) */ + fp->_flags |= __SMOD; /* soon */ + diff = p - fp->_p; + len += diff; + if (__slbexpand(fp, len)) + goto error; + (void) memcpy((void *)(fp->_lb._base + off), (void *)fp->_p, diff); + fp->_r -= diff + 1; + fp->_p = p + 1; + break; + } + if (lenp != NULL) + *lenp = len; + fp->_lb._base[len] = 0; + + funlockfile(fp); + return ((char *)fp->_lb._base); + +error: + if (lenp != NULL) + *lenp = 0; /* ??? */ + funlockfile(fp); + return (NULL); /* ??? */ +} |