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
12 fstat — get file status
13
15 #include <sys/stat.h>
16 int fstat(int fildes, struct stat *buf);
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20 The fstat() function shall obtain information about an open file asso‐
21 ciated with the file descriptor fildes, and shall write it to the area
22 pointed to by buf.
23 If fildes references a shared memory object, the implementation shall
25 update in the stat structure pointed to by the buf argument the st_uid,
26 st_gid, st_size, and st_mode fields, and only the S_IRUSR, S_IWUSR,
27 S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be
28 valid. The implementation may update other fields and flags.
29 If fildes references a typed memory object, the implementation shall
31 update in the stat structure pointed to by the buf argument the st_uid,
32 st_gid, st_size, and st_mode fields, and only the S_IRUSR, S_IWUSR,
33 S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be
34 valid. The implementation may update other fields and flags.
35 The buf argument is a pointer to a stat structure, as defined in
37 <sys/stat.h>, into which information is placed concerning the file.
38 For all other file types defined in this volume of POSIX.1‐2017, the
40 structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atim,
41 st_ctim, and st_mtim shall have meaningful values and the value of the
42 st_nlink member shall be set to the number of links to the file.
43 An implementation that provides additional or alternative file access
45 control mechanisms may, under implementation-defined conditions, cause
46 fstat() to fail.
47 The fstat() function shall update any time-related fields (as described
49 in the Base Definitions volume of POSIX.1‐2017, Section 4.9, File Times
50 Update), before writing into the stat structure.
51
53 Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
54 returned and errno set to indicate the error.
55
57 The fstat() function shall fail if:
58 EBADF The fildes argument is not a valid file descriptor.
60 EIO An I/O error occurred while reading from the file system.
62 EOVERFLOW
64 The file size in bytes or the number of blocks allocated to the
65 file or the file serial number cannot be represented correctly
66 in the structure pointed to by buf.
67 The fstat() function may fail if:
69 EOVERFLOW
71 One of the values is too large to store into the structure
72 pointed to by the buf argument.
73 The following sections are informative.
75
77 Obtaining File Status Information
78 The following example shows how to obtain file status information for a
79 file named /home/cnd/mod1. The structure variable buffer is defined
80 for the stat structure. The /home/cnd/mod1 file is opened with
81 read/write privileges and is passed to the open file descriptor fildes.
82 #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.
96
98 None.
99
101 None.
102
104 fstatat()
105 The Base Definitions volume of POSIX.1‐2017, Section 4.9, 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 1003.1-2017, Standard for Information Technology -- Por‐
112 table Operating System Interface (POSIX), The Open Group Base Specifi‐
113 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
114 Electrical and Electronics Engineers, Inc and The Open Group. In the
115 event of any discrepancy between this version and the original IEEE and
116 The Open Group Standard, the original IEEE and The Open Group Standard
117 is the referee document. The original Standard can be obtained online
118 at http://www.opengroup.org/unix/online.html .
119 Any typographical or formatting errors that appear in this page are
121 most likely to have been introduced during the conversion of the source
122 files to man page format. To report such errors, see https://www.ker‐
123 nel.org/doc/man-pages/reporting_bugs.html .
124IEEE/The Open Group 2017 FSTAT(3P)