1FCHOWN(3P) POSIX Programmer's Manual FCHOWN(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 fchown — change owner and group of a file
14
16 #include <unistd.h>
17 int fchown(int fildes, uid_t owner, gid_t group);
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21 The fchown() function shall be equivalent to chown() except that the
22 file whose owner and group are changed is specified by the file
23 descriptor fildes.
24
26 Upon successful completion, fchown() shall return 0. Otherwise, it
27 shall return −1 and set errno to indicate the error.
28
30 The fchown() function shall fail if:
31 EBADF The fildes argument is not an open file descriptor.
33 EPERM The effective user ID does not match the owner of the file or
35 the process does not have appropriate privileges and
36 _POSIX_CHOWN_RESTRICTED indicates that such privilege is
37 required.
38 EROFS The file referred to by fildes resides on a read-only file sys‐
40 tem.
41 The fchown() function may fail if:
43 EINVAL The owner or group ID is not a value supported by the implemen‐
45 tation. The fildes argument refers to a pipe or socket or an
46 fattach()-ed STREAM and the implementation disallows execution
47 of fchown() on a pipe.
48 EIO A physical I/O error has occurred.
50 EINTR The fchown() function was interrupted by a signal which was
52 caught.
53 The following sections are informative.
55
57 Changing the Current Owner of a File
58 The following example shows how to change the owner of a file named
59 /home/cnd/mod1 to ``jones'' and the group to ``cnd''.
60 The numeric value for the user ID is obtained by extracting the user ID
62 from the user database entry associated with ``jones''. Similarly, the
63 numeric value for the group ID is obtained by extracting the group ID
64 from the group database entry associated with ``cnd''. This example
65 assumes the calling program has appropriate privileges.
66 #include <sys/types.h>
68 #include <unistd.h>
69 #include <fcntl.h>
70 #include <pwd.h>
71 #include <grp.h>
72 struct passwd *pwd;
74 struct group *grp;
75 int fildes;
76 ...
77 fildes = open("/home/cnd/mod1", O_RDWR);
78 pwd = getpwnam("jones");
79 grp = getgrnam("cnd");
80 fchown(fildes, pwd->pw_uid, grp->gr_gid);
81
83 None.
84
86 None.
87
89 None.
90
92 chown()
93 The Base Definitions volume of POSIX.1‐2008, <unistd.h>
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97 Portions of this text are reprinted and reproduced in electronic form
98 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
99 -- Portable Operating System Interface (POSIX), The Open Group Base
100 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
101 cal and Electronics Engineers, Inc and The Open Group. (This is
102 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
103 event of any discrepancy between this version and the original IEEE and
104 The Open Group Standard, the original IEEE and The Open Group Standard
105 is the referee document. The original Standard can be obtained online
106 at http://www.unix.org/online.html .
107 Any typographical or formatting errors that appear in this page are
109 most likely to have been introduced during the conversion of the source
110 files to man page format. To report such errors, see https://www.ker‐
111 nel.org/doc/man-pages/reporting_bugs.html .
112IEEE/The Open Group 2013 FCHOWN(3P)