chroot

Purpose

     Changes the effective root directory.

Syntax

     int chroot (path)
     char *path;

Description

     The chroot system call causes  the directory named by the
     path parameter  to become  the effective  root directory.
     If Distributed Services is installed on your system, this
     path  can cross  into another  node.  The  effective root
     directory is the starting point when searching for a file
     whose  path  name begins  with  /  (slash).  The  current
     directory is not affected by the chroot system call.

      The  effective user  ID of the  calling process  must be
     superuser to change the effective root directory.

     The ".." (dot-dot) entry  in the effective root directory
     is  interpreted  to  mean the  effective  root  directory
     itself.  Thus,  ".." (dot-dot)  cannot be used  to access
     files outside  the subtree  rooted at the  effective root
     directory.

Return Value

     Upon successful completion, a value of 0 is returned.  If
     the chroot system  call fails, a value of  -1 is returned
     and errno is set to indicate the error.

Diagnostics

     The  chroot  system call  fails  and  the effective  root
     directory remains  unchanged if one  or more of  the fol-
     lowing are true:

     ENOTDIR    Any component of the path name is not a direc-
                tory.

     ENOENT     The named directory does not exist.

     EPERM      The effective  user ID of the  calling process
                is not superuser.

     EFAULT     The path parameter &pointsout..

     ESTALE     The  process's root  or  current directory  is
                located in a virtual file system that has been
                unmounted.

     If  Distributed Services  is  installed  on your  system,
     chroot can also fail if one  or more of the following are
     true:

     EACCES        Search permission was denied on a component
                   of the path.

                   The  effective  user   ID  of  the  calling
                   process must  be the same as  the superuser
                   ID to issue this call.  Since with Distrib-
                   uted Services  path can cross  into another
                   node  and  a  process  that  has  superuser
                   authority in  the local node  probably does
                   not have superuser  authority in the remote
                   node, search permission  may be denied even
                   to the local superuser.

     EDIST         The   server   has  blocked   new   inbound
                   requests.

     EDIST         Outbound requests are currently blocked.

     EDIST         The server has a  release level of Distrib-
                   uted Services that  cannot communicate with
                   this node.

     EAGAIN        The  server  is  too  busy  to  accept  the
                   request.

     ESTALE        The file  descriptor for a remote  file has
                   become obsolete.

     EPERM         The translate tables of  the server did not
                   contain any entry  for either the effective
                   user  ID  or  effective  group  ID  of  the
                   calling process.

     ENODEV        The named file is  a remote file located on
                   a  device that  has been  unmounted at  the
                   server.

     ENOMEM        Either  this node  or the  server does  not
                   have enough memory available to service the
                   request.

     ENOCONNECT    An attempt to establish  a new network con-
                   nection with a remote node failed.

     EBADCONNECT   An attempt to use  an existing network con-
                   nection with a remote node failed.

Related Information

     In this book:  "chdir."

     The chroot command in  AIX Operating System Commands Ref-
     erence.