diff options
author | Corinna Vinschen <corinna@vinschen.de> | 2012-11-29 16:28:30 +0000 |
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committer | Corinna Vinschen <corinna@vinschen.de> | 2012-11-29 16:28:30 +0000 |
commit | 0772f3f1c18483ff69b4a4cec918df39596eae5c (patch) | |
tree | ad788e069002f5924f39d5f624368177a6223d97 /newlib/libc/stdio/ftello.c | |
parent | 0d829d9695a57a37203b1ef1e4ca812bd1fb2fb1 (diff) | |
download | cygnal-0772f3f1c18483ff69b4a4cec918df39596eae5c.tar.gz cygnal-0772f3f1c18483ff69b4a4cec918df39596eae5c.tar.bz2 cygnal-0772f3f1c18483ff69b4a4cec918df39596eae5c.zip |
* libc/include/sys/reent.h (__sFILE): Change type of _offset
from int to _off_t.
* libc/stdio/ftell.c: Use _ftello_r().
* libc/stdio/ftello.c: Copy implementation from previous
_ftell_r().
* libc/stdio/fseek.c: Use _fseeko_r().
* libc/stdio/fseeko.c: Copy implementation from previous
_fseek_r().
Diffstat (limited to 'newlib/libc/stdio/ftello.c')
-rw-r--r-- | newlib/libc/stdio/ftello.c | 140 |
1 files changed, 136 insertions, 4 deletions
diff --git a/newlib/libc/stdio/ftello.c b/newlib/libc/stdio/ftello.c index 216d88453..3a1885e81 100644 --- a/newlib/libc/stdio/ftello.c +++ b/newlib/libc/stdio/ftello.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2002, Red Hat Inc. + * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted @@ -15,17 +15,149 @@ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ +/* +FUNCTION +<<ftell>>, <<ftello>>---return position in a stream or file + +INDEX + ftell +INDEX + ftello +INDEX + _ftell_r +INDEX + _ftello_r + +ANSI_SYNOPSIS + #include <stdio.h> + long ftell(FILE *<[fp]>); + off_t ftello(FILE *<[fp]>); + long _ftell_r(struct _reent *<[ptr]>, FILE *<[fp]>); + off_t _ftello_r(struct _reent *<[ptr]>, FILE *<[fp]>); + +TRAD_SYNOPSIS + #include <stdio.h> + long ftell(<[fp]>) + FILE *<[fp]>; + + off_t ftello(<[fp]>) + FILE *<[fp]>; + + long _ftell_r(<[ptr]>, <[fp]>) + struct _reent *<[ptr]>; + FILE *<[fp]>; + + off_t _ftello_r(<[ptr]>, <[fp]>) + struct _reent *<[ptr]>; + FILE *<[fp]>; + +DESCRIPTION +Objects of type <<FILE>> can have a ``position'' that records how much +of the file your program has already read. Many of the <<stdio>> functions +depend on this position, and many change it as a side effect. + +The result of <<ftell>>/<<ftello>> is the current position for a file +identified by <[fp]>. If you record this result, you can later +use it with <<fseek>>/<<fseeko>> to return the file to this +position. The difference between <<ftell>> and <<ftello>> is that +<<ftell>> returns <<long>> and <<ftello>> returns <<off_t>>. + +In the current implementation, <<ftell>>/<<ftello>> simply uses a character +count to represent the file position; this is the same number that +would be recorded by <<fgetpos>>. + +RETURNS +<<ftell>>/<<ftello>> return the file position, if possible. If they cannot do +this, they return <<-1L>>. Failure occurs on streams that do not support +positioning; the global <<errno>> indicates this condition with the +value <<ESPIPE>>. + +PORTABILITY +<<ftell>> is required by the ANSI C standard, but the meaning of its +result (when successful) is not specified beyond requiring that it be +acceptable as an argument to <<fseek>>. In particular, other +conforming C implementations may return a different result from +<<ftell>> than what <<fgetpos>> records. + +<<ftello>> is defined by the Single Unix specification. + +No supporting OS subroutines are required. +*/ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "%W% (Berkeley) %G%"; +#endif /* LIBC_SCCS and not lint */ + +/* + * ftello: return current offset. + */ + #include <_ansi.h> #include <reent.h> #include <stdio.h> +#include <errno.h> +#include "local.h" _off_t _DEFUN(_ftello_r, (ptr, fp), struct _reent * ptr _AND register FILE * fp) { - /* for now we simply cast since off_t should be long */ - return (_off_t)_ftell_r (ptr, fp); + _fpos_t pos; + + /* Ensure stdio is set up. */ + + CHECK_INIT (ptr, fp); + + _newlib_flockfile_start (fp); + + if (fp->_seek == NULL) + { + ptr->_errno = ESPIPE; + _newlib_flockfile_exit (fp); + return -1L; + } + + /* Find offset of underlying I/O object, then adjust for buffered + bytes. Flush a write stream, since the offset may be altered if + the stream is appending. Do not flush a read stream, since we + must not lose the ungetc buffer. */ + if (fp->_flags & __SWR) + _fflush_r (ptr, fp); + if (fp->_flags & __SOFF) + pos = fp->_offset; + else + { + pos = fp->_seek (ptr, fp->_cookie, (_fpos_t) 0, SEEK_CUR); + if (pos == -1L) + { + _newlib_flockfile_exit (fp); + return pos; + } + } + if (fp->_flags & __SRD) + { + /* + * Reading. Any unread characters (including + * those from ungetc) cause the position to be + * smaller than that in the underlying object. + */ + pos -= fp->_r; + if (HASUB (fp)) + pos -= fp->_ur; + } + else if ((fp->_flags & __SWR) && fp->_p != NULL) + { + /* + * Writing. Any buffered characters cause the + * position to be greater than that in the + * underlying object. + */ + pos += fp->_p - fp->_bf._base; + } + + _newlib_flockfile_end (fp); + return pos; } #ifndef _REENT_ONLY @@ -34,7 +166,7 @@ _off_t _DEFUN(ftello, (fp), register FILE * fp) { - return (_off_t)_ftell_r (_REENT, fp); + return _ftello_r (_REENT, fp); } #endif /* !_REENT_ONLY */ |