From be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da Mon Sep 17 00:00:00 2001 From: rgrimes Date: Fri, 27 May 1994 05:00:24 +0000 Subject: BSD 4.4 Lite Lib Sources --- lib/libc/stdio/fseek.3 | 188 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 lib/libc/stdio/fseek.3 (limited to 'lib/libc/stdio/fseek.3') diff --git a/lib/libc/stdio/fseek.3 b/lib/libc/stdio/fseek.3 new file mode 100644 index 0000000..4d22276 --- /dev/null +++ b/lib/libc/stdio/fseek.3 @@ -0,0 +1,188 @@ +.\" Copyright (c) 1990, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" Chris Torek and the American National Standards Committee X3, +.\" on Information Processing Systems. +.\" +.\" 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. +.\" +.\" @(#)fseek.3 8.1 (Berkeley) 6/4/93 +.\" +.Dd June 4, 1993 +.Dt FSEEK 3 +.Os +.Sh NAME +.Nm fgetpos , +.Nm fseek , +.Nm fsetpos , +.Nm ftell , +.Nm rewind +.Nd reposition a stream +.Sh SYNOPSIS +.Fd #include +.Ft int +.Fn fseek "FILE *stream" "long offset" "int whence" +.Ft long +.Fn ftell "FILE *stream" +.Ft void +.Fn rewind "FILE *stream" +.Ft int +.Fn fgetpos "FILE *stream" "fpos_t *pos" +.Ft int +.Fn fsetpos "FILE *stream" "fpos_t *pos" +.Sh DESCRIPTION +The +.Fn fseek +function sets the file position indicator for the stream pointed +to by +.Fa stream . +The new position, measured in bytes, is obtained by adding +.Fa offset +bytes to the position specified by +.Fa whence . +If +.Fa whence +is set to +.Dv SEEK_SET , +.Dv SEEK_CUR , +or +.Dv SEEK_END , +the offset is relative to the +start of the file, the current position indicator, or end-of-file, +respectively. +A successful call to the +.Fn fseek +function clears the end-of-file indicator for the stream and undoes +any effects of the +.Xr ungetc 3 +function on the same stream. +.Pp +The +.Fn ftell +function +obtains the current value of the file position indicator for the +stream pointed to by +.Fa stream . +.Pp +The +.Fn rewind +function sets the file position indicator for the stream pointed +to by +.Fa stream +to the beginning of the file. +It is equivalent to: +.Pp +.Dl (void)fseek(stream, 0L, SEEK_SET) +.Pp +except that the error indicator for the stream is also cleared +(see +.Xr clearerr 3 ) . +.Pp +The +.Fn fgetpos +and +.Fn fsetpos +functions +are alternate interfaces equivalent to +.Fn ftell +and +.Fn fseek +(with whence set to +.Dv SEEK_SET +), setting and storing the current value of +the file offset into or from the object referenced by +.Fa pos . +On some +.Pq non- Ns Tn UNIX +systems an +.Dq Fa fpos_t +object may be a complex object +and these routines may be the only way to portably reposition a text stream. +.Sh RETURN VALUES +The +.Fn rewind +function +returns no value. +Upon successful completion, +.Fn fgetpos , +.Fn fseek , +.Fn fsetpos +return 0, +and +.Fn ftell +returns the current offset. +Otherwise, \-1 is returned and the global variable errno is set to +indicate the error. +.Sh ERRORS +.Bl -tag -width [EINVAL] +.It Bq Er EBADF +The +.Fa stream +specified +is not a seekable stream. +.It Bq Er EINVAL +The +.Fa whence +argument to +.Fn fseek +was not +.Dv SEEK_SET , +.Dv SEEK_END , +or +.Dv SEEK_CUR . +.El +.Pp +The function +.Fn fgetpos , +.Fn fseek , +.Fn fsetpos , +and +.Fn ftell +may also fail and set +.Va errno +for any of the errors specified for the routines +.Xr fflush 3 , +.Xr fstat 2 , +.Xr lseek 2 , +and +.Xr malloc 3 . +.Sh SEE ALSO +.Xr lseek 2 +.Sh STANDARDS +The +.Fn fgetpos , +.Fn fsetpos , +.Fn fseek , +.Fn ftell , +and +.Fn rewind +functions +conform to +.St -ansiC . -- cgit v1.1