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author | Christopher Faylor <me@cgf.cx> | 2000-02-17 19:39:52 +0000 |
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committer | Christopher Faylor <me@cgf.cx> | 2000-02-17 19:39:52 +0000 |
commit | 8a0efa53e44919bcf5ccb1d3353618a82afdf8bc (patch) | |
tree | 68c3dbf3f2c6fd5d49777def9914d77b5cd4589d /newlib/libc/stdio/fread.c | |
parent | 1fd5e000ace55b323124c7e556a7a864b972a5c4 (diff) | |
download | cygnal-8a0efa53e44919bcf5ccb1d3353618a82afdf8bc.tar.gz cygnal-8a0efa53e44919bcf5ccb1d3353618a82afdf8bc.tar.bz2 cygnal-8a0efa53e44919bcf5ccb1d3353618a82afdf8bc.zip |
import newlib-2000-02-17 snapshot
Diffstat (limited to 'newlib/libc/stdio/fread.c')
-rw-r--r-- | newlib/libc/stdio/fread.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/newlib/libc/stdio/fread.c b/newlib/libc/stdio/fread.c new file mode 100644 index 000000000..4de7ce290 --- /dev/null +++ b/newlib/libc/stdio/fread.c @@ -0,0 +1,97 @@ +/* + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +/* +FUNCTION +<<fread>>---read array elements from a file + +INDEX + fread + +ANSI_SYNOPSIS + #include <stdio.h> + size_t fread(void *<[buf]>, size_t <[size]>, size_t <[count]>, + FILE *<[fp]>); + +TRAD_SYNOPSIS + #include <stdio.h> + size_t fread(<[buf]>, <[size]>, <[count]>, <[fp]>) + char *<[buf]>; + size_t <[size]>; + size_t <[count]>; + FILE *<[fp]>; + +DESCRIPTION +<<fread>> attempts to copy, from the file or stream identified by +<[fp]>, <[count]> elements (each of size <[size]>) into memory, +starting at <[buf]>. <<fread>> may copy fewer elements than +<[count]> if an error, or end of file, intervenes. + +<<fread>> also advances the file position indicator (if any) for +<[fp]> by the number of @emph{characters} actually read. + +RETURNS +The result of <<fread>> is the number of elements it succeeded in +reading. + +PORTABILITY +ANSI C requires <<fread>>. + +Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, +<<lseek>>, <<read>>, <<sbrk>>, <<write>>. +*/ + +#include <stdio.h> +#include <string.h> +#include "local.h" + +size_t +_DEFUN (fread, (buf, size, count, fp), + _PTR buf _AND + size_t size _AND + size_t count _AND + FILE * fp) +{ + register size_t resid; + register char *p; + register int r; + size_t total; + + if ((resid = count * size) == 0) + return 0; + if (fp->_r < 0) + fp->_r = 0; + total = resid; + p = buf; + while (resid > (r = fp->_r)) + { + (void) memcpy ((void *) p, (void *) fp->_p, (size_t) r); + fp->_p += r; + /* fp->_r = 0 ... done in __srefill */ + p += r; + resid -= r; + if (__srefill (fp)) + { + /* no more input: return partial result */ + return (total - resid) / size; + } + } + (void) memcpy ((void *) p, (void *) fp->_p, resid); + fp->_r -= resid; + fp->_p += resid; + return count; +} |