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
12 fchown — change owner and group of a file
13
15 #include <unistd.h>
16 int fchown(int fildes, uid_t owner, gid_t group);
18
20 The fchown() function shall be equivalent to chown() except that the
21 file whose owner and group are changed is specified by the file
22 descriptor fildes.
23
25 Upon successful completion, fchown() shall return 0. Otherwise, it
26 shall return -1 and set errno to indicate the error.
27
29 The fchown() function shall fail if:
30 EBADF The fildes argument is not an open file descriptor.
32 EPERM The effective user ID does not match the owner of the file or
34 the process does not have appropriate privileges and
35 _POSIX_CHOWN_RESTRICTED indicates that such privilege is
36 required.
37 EROFS The file referred to by fildes resides on a read-only file sys‐
39 tem.
40 The fchown() function may fail if:
42 EINVAL The owner or group ID is not a value supported by the implemen‐
44 tation. The fildes argument refers to a pipe or socket or an
45 fattach()-ed STREAM and the implementation disallows execution
46 of fchown() on a pipe.
47 EIO A physical I/O error has occurred.
49 EINTR The fchown() function was interrupted by a signal which was
51 caught.
52 The following sections are informative.
54
56 Changing the Current Owner of a File
57 The following example shows how to change the owner of a file named
58 /home/cnd/mod1 to ``jones'' and the group to ``cnd''.
59 The numeric value for the user ID is obtained by extracting the user ID
61 from the user database entry associated with ``jones''. Similarly, the
62 numeric value for the group ID is obtained by extracting the group ID
63 from the group database entry associated with ``cnd''. This example
64 assumes the calling program has appropriate privileges.
65 #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.1‐2017, <unistd.h>
95
97 Portions of this text are reprinted and reproduced in electronic form
98 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
99 table Operating System Interface (POSIX), The Open Group Base Specifi‐
100 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
101 Electrical and Electronics Engineers, Inc and The Open Group. In the
102 event of any discrepancy between this version and the original IEEE and
103 The Open Group Standard, the original IEEE and The Open Group Standard
104 is the referee document. The original Standard can be obtained online
105 at http://www.opengroup.org/unix/online.html .
106 Any typographical or formatting errors that appear in this page are
108 most likely to have been introduced during the conversion of the source
109 files to man page format. To report such errors, see https://www.ker‐
110 nel.org/doc/man-pages/reporting_bugs.html .
111IEEE/The Open Group 2017 FCHOWN(3P)