1FSETPOS(3P) POSIX Programmer's Manual FSETPOS(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 fsetpos — set current file position
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16 #include <stdio.h>
17 int fsetpos(FILE *stream, const fpos_t *pos);
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21 The functionality described on this reference page is aligned with the
22 ISO C standard. Any conflict between the requirements described here
23 and the ISO C standard is unintentional. This volume of POSIX.1‐2008
24 defers to the ISO C standard.
25 The fsetpos() function shall set the file position and state indicators
27 for the stream pointed to by stream according to the value of the
28 object pointed to by pos, which the application shall ensure is a value
29 obtained from an earlier call to fgetpos() on the same stream. If a
30 read or write error occurs, the error indicator for the stream shall be
31 set and fsetpos() fails.
32 A successful call to the fsetpos() function shall clear the end-of-file
34 indicator for the stream and undo any effects of ungetc() on the same
35 stream. After an fsetpos() call, the next operation on an update stream
36 may be either input or output.
37 The behavior of fsetpos() on devices which are incapable of seeking is
39 implementation-defined. The value of the file offset associated with
40 such a device is undefined.
41 The fsetpos() function shall not change the setting of errno if suc‐
43 cessful.
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46 The fsetpos() function shall return 0 if it succeeds; otherwise, it
47 shall return a non-zero value and set errno to indicate the error.
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50 The fsetpos() function shall fail if, either the stream is unbuffered
51 or the stream's buffer needed to be flushed, and the call to fsetpos()
52 causes an underlying lseek() or write() to be invoked, and:
53 EAGAIN The O_NONBLOCK flag is set for the file descriptor and the
55 thread would be delayed in the write operation.
56 EBADF The file descriptor underlying the stream file is not open for
58 writing or the stream's buffer needed to be flushed and the file
59 is not open.
60 EFBIG An attempt was made to write a file that exceeds the maximum
62 file size.
63 EFBIG An attempt was made to write a file that exceeds the file size
65 limit of the process.
66 EFBIG The file is a regular file and an attempt was made to write at
68 or beyond the offset maximum associated with the corresponding
69 stream.
70 EINTR The write operation was terminated due to the receipt of a sig‐
72 nal, and no data was transferred.
73 EIO A physical I/O error has occurred, or the process is a member of
75 a background process group attempting to perform a write() to
76 its controlling terminal, TOSTOP is set, the calling thread is
77 not blocking SIGTTOU, the process is not ignoring SIGTTOU, and
78 the process group of the process is orphaned. This error may
79 also be returned under implementation-defined conditions.
80 ENOSPC There was no free space remaining on the device containing the
82 file.
83 EPIPE An attempt was made to write to a pipe or FIFO that is not open
85 for reading by any process; a SIGPIPE signal shall also be sent
86 to the thread.
87 ESPIPE The file descriptor underlying stream is associated with a pipe,
89 FIFO, or socket.
90 The fsetpos() function may fail if:
92 ENXIO A request was made of a nonexistent device, or the request was
94 outside the capabilities of the device.
95 The following sections are informative.
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99 None.
100
102 None.
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105 None.
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108 None.
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111 Section 2.5, Standard I/O Streams, fopen(), ftell(), lseek(), rewind(),
112 ungetc(), write()
113 The Base Definitions volume of POSIX.1‐2008, <stdio.h>
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117 Portions of this text are reprinted and reproduced in electronic form
118 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
119 -- Portable Operating System Interface (POSIX), The Open Group Base
120 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
121 cal and Electronics Engineers, Inc and The Open Group. (This is
122 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
123 event of any discrepancy between this version and the original IEEE and
124 The Open Group Standard, the original IEEE and The Open Group Standard
125 is the referee document. The original Standard can be obtained online
126 at http://www.unix.org/online.html .
127 Any typographical or formatting errors that appear in this page are
129 most likely to have been introduced during the conversion of the source
130 files to man page format. To report such errors, see https://www.ker‐
131 nel.org/doc/man-pages/reporting_bugs.html .
132IEEE/The Open Group 2013 FSETPOS(3P)