1FSTAT(3P) POSIX Programmer's Manual FSTAT(3P)
2
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.
10
13 fstat — get file status
14
16 #include <sys/stat.h>
17 int fstat(int fildes, struct stat *buf);
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21 The fstat() function shall obtain information about an open file asso‐
22 ciated with the file descriptor fildes, and shall write it to the area
23 pointed to by buf.
24 If fildes references a shared memory object, the implementation shall
26 update in the stat structure pointed to by the buf argument the st_uid,
27 st_gid, st_size, and st_mode fields, and only the S_IRUSR, S_IWUSR,
28 S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be
29 valid. The implementation may update other fields and flags.
30 If fildes references a typed memory object, the implementation shall
32 update in the stat structure pointed to by the buf argument the st_uid,
33 st_gid, st_size, and st_mode fields, and only the S_IRUSR, S_IWUSR,
34 S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be
35 valid. The implementation may update other fields and flags.
36 The buf argument is a pointer to a stat structure, as defined in
38 <sys/stat.h>, into which information is placed concerning the file.
39 For all other file types defined in this volume of POSIX.1‐2008, the
41 structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atim,
42 st_ctim, and st_mtim shall have meaningful values and the value of the
43 st_nlink member shall be set to the number of links to the file.
44 An implementation that provides additional or alternative file access
46 control mechanisms may, under implementation-defined conditions, cause
47 fstat() to fail.
48 The fstat() function shall update any time-related fields (as described
50 in the Base Definitions volume of POSIX.1‐2008, Section 4.8, File Times
51 Update), before writing into the stat structure.
52
54 Upon successful completion, 0 shall be returned. Otherwise, −1 shall be
55 returned and errno set to indicate the error.
56
58 The fstat() function shall fail if:
59 EBADF The fildes argument is not a valid file descriptor.
61 EIO An I/O error occurred while reading from the file system.
63 EOVERFLOW
65 The file size in bytes or the number of blocks allocated to the
66 file or the file serial number cannot be represented correctly
67 in the structure pointed to by buf.
68 The fstat() function may fail if:
70 EOVERFLOW
72 One of the values is too large to store into the structure
73 pointed to by the buf argument.
74 The following sections are informative.
76
78 Obtaining File Status Information
79 The following example shows how to obtain file status information for a
80 file named /home/cnd/mod1. The structure variable buffer is defined
81 for the stat structure. The /home/cnd/mod1 file is opened with
82 read/write privileges and is passed to the open file descriptor fildes.
83 #include <sys/types.h>
85 #include <sys/stat.h>
86 #include <fcntl.h>
87 struct stat buffer;
89 int status;
90 ...
91 fildes = open("/home/cnd/mod1", O_RDWR);
92 status = fstat(fildes, &buffer);
93
95 None.
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98 None.
99
101 None.
102
104 fstatat()
105 The Base Definitions volume of POSIX.1‐2008, Section 4.8, File Times
107 Update, <sys_stat.h>, <sys_types.h>
108
110 Portions of this text are reprinted and reproduced in electronic form
111 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
112 -- Portable Operating System Interface (POSIX), The Open Group Base
113 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
114 cal and Electronics Engineers, Inc and The Open Group. (This is
115 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
116 event of any discrepancy between this version and the original IEEE and
117 The Open Group Standard, the original IEEE and The Open Group Standard
118 is the referee document. The original Standard can be obtained online
119 at http://www.unix.org/online.html .
120 Any typographical or formatting errors that appear in this page are
122 most likely to have been introduced during the conversion of the source
123 files to man page format. To report such errors, see https://www.ker‐
124 nel.org/doc/man-pages/reporting_bugs.html .
125IEEE/The Open Group 2013 FSTAT(3P)