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32 .\" @(#)chroot.2 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/sys/chroot.2,v 1.7.2.8 2002/12/11 14:06:37 ru Exp $
40 .Nd change root directory
46 .Fn chroot "const char *dirname"
49 is the address of the pathname of a directory, terminated by an ASCII NUL.
53 to become the root directory,
54 that is, the starting point for path searches of pathnames
58 In order for a directory to become the root directory
59 a process must have execute (search) access for that directory.
61 It should be noted that
63 has no effect on the process's current directory.
65 This call is restricted to the super-user.
67 Depending on the setting of the
68 .Ql kern.chroot_allow_open_directories
69 sysctl variable, open filedescriptors which reference directories
75 .Ql kern.chroot_allow_open_directories
80 if there are any directories open.
83 .Ql kern.chroot_allow_open_directories
84 is set to one (the default),
88 if there are any directories open and the
89 process is already subject to a
94 .Ql kern.chroot_allow_open_directories
95 will bypass the check for open directories
97 Upon successful completion, a value of 0 is returned. Otherwise,
98 a value of -1 is returned and
100 is set to indicate an error.
103 will fail and the root directory will be unchanged if:
106 A component of the path name is not a directory.
108 The effective user ID is not the super-user, or one or more
109 filedescriptors are open directories.
110 .It Bq Er ENAMETOOLONG
111 A component of a pathname exceeded 255 characters,
112 or an entire path name exceeded 1023 characters.
114 The named directory does not exist.
116 Search permission is denied for any component of the path name.
118 Too many symbolic links were encountered in translating the pathname.
121 points outside the process's allocated address space.
123 An I/O error occurred while reading from or writing to the file system.
131 function call appeared in