fsetpos(3p) — Linux manual page


FSETPOS(3P)             POSIX Programmer's Manual            FSETPOS(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       fsetpos — set current file position

SYNOPSIS         top

       #include <stdio.h>

       int fsetpos(FILE *stream, const fpos_t *pos);

DESCRIPTION         top

       The functionality described on this reference page is aligned
       with the ISO C standard. Any conflict between the requirements
       described here and the ISO C standard is unintentional. This
       volume of POSIX.1‐2017 defers to the ISO C standard.

       The fsetpos() function shall set the file position and state
       indicators for the stream pointed to by stream according to the
       value of the object pointed to by pos, which the application
       shall ensure is a value obtained from an earlier call to
       fgetpos() on the same stream. If a read or write error occurs,
       the error indicator for the stream shall be set and fsetpos()

       A successful call to the fsetpos() function shall clear the end-
       of-file indicator for the stream and undo any effects of ungetc()
       on the same stream. After an fsetpos() call, the next operation
       on an update stream may be either input or output.

       The behavior of fsetpos() on devices which are incapable of
       seeking is implementation-defined.  The value of the file offset
       associated with such a device is undefined.

       The fsetpos() function shall not change the setting of errno if

RETURN VALUE         top

       The fsetpos() function shall return 0 if it succeeds; otherwise,
       it shall return a non-zero value and set errno to indicate the

ERRORS         top

       The fsetpos() function shall fail if, either the stream is
       unbuffered or the stream's buffer needed to be flushed, and the
       call to fsetpos() causes an underlying lseek() or write() to be
       invoked, and:

       EAGAIN The O_NONBLOCK flag is set for the file descriptor and the
              thread would be delayed in the write operation.

       EBADF  The file descriptor underlying the stream file is not open
              for writing or the stream's buffer needed to be flushed
              and the file is not open.

       EFBIG  An attempt was made to write a file that exceeds the
              maximum file size.

       EFBIG  An attempt was made to write a file that exceeds the file
              size limit of the process.

       EFBIG  The file is a regular file and an attempt was made to
              write at or beyond the offset maximum associated with the
              corresponding stream.

       EINTR  The write operation was terminated due to the receipt of a
              signal, and no data was transferred.

       EIO    A physical I/O error has occurred, or the process is a
              member of a background process group attempting to perform
              a write() to its controlling terminal, TOSTOP is set, the
              calling thread is not blocking SIGTTOU, the process is not
              ignoring SIGTTOU, and the process group of the process is
              orphaned.  This error may also be returned under
              implementation-defined conditions.

       ENOSPC There was no free space remaining on the device containing
              the file.

       EPIPE  An attempt was made to write to a pipe or FIFO that is not
              open for reading by any process; a SIGPIPE signal shall
              also be sent to the thread.

       ESPIPE The file descriptor underlying stream is associated with a
              pipe, FIFO, or socket.

       The fsetpos() function may fail if:

       ENXIO  A request was made of a nonexistent device, or the request
              was outside the capabilities of the device.

       The following sections are informative.

EXAMPLES         top




RATIONALE         top




SEE ALSO         top

       Section 2.5, Standard I/O Streams, fopen(3p), ftell(3p),
       lseek(3p), rewind(3p), ungetc(3p), write(3p)

       The Base Definitions volume of POSIX.1‐2017, stdio.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                       FSETPOS(3P)

Pages that refer to this page: stdio.h(0p)fseek(3p)ungetc(3p)ungetwc(3p)