chacl - change the access control list of a file or directory


   chacl acl pathname...
   chacl -b acl dacl pathname...
   chacl -d dacl pathname...
   chacl -R pathname...
   chacl -D pathname...
   chacl -B pathname...
   chacl -l pathname...
   chacl -r pathname...


   chacl  is  an  IRIX-compatibility  command, and is maintained for those
   users who are familiar with its use from either XFS or IRIX.  Refer  to
   the  SEE  ALSO  section  below for a description of tools which conform
   more closely to the (withdrawn  draft)  POSIX  1003.1e  standard  which
   describes Access Control Lists (ACLs).

   chacl changes the ACL(s) for a file or directory.  The ACL(s) specified
   are applied to each file in the pathname arguments.

   Each ACL is a string which is interpreted  using  the  acl_from_text(3)
   routine.   These strings are made up of comma separated clauses each of
   which is of the form, tag:name:perm.  Where tag can be:

   "user" (or "u")
          indicating that the entry is a user ACL entry.

   "group" (or "g")
          indicating that the entry is a group ACL entry.

   "other" (or "o")
          indicating that the entry is an other ACL entry.

   "mask" (or "m")
          indicating that the entry is a mask ACL entry.

   name is a string which is the user or group name for the ACL entry.   A
   null  name  in  a user or group ACL entry indicates the file's owner or
   file's group.  perm is the string "rwx" where each of the  entries  may
   be  replaced  by  a  "-" indicating no access of that type, e.g. "r-x",
   "--x", "---".


   -b     Indicates that there are two ACLs to change, the  first  is  the
          file access ACL and the second the directory default ACL.

   -d     Used to set only the default ACL of a directory.

   -R     Removes the file access ACL only.

   -D     Removes directory default ACL only.

   -B     Remove all ACLs.

   -l     Lists  the  access  ACL  and possibly the default ACL associated
          with the specified files or directories.  This option was  added
          during the Linux port of XFS, and is not IRIX compatible.

   -r     Set  the  access  ACL  recursively  for  each  subtree rooted at
          pathname(s).  This option was also added during the  Linux  port
          of XFS, and is not compatible with IRIX.


   A minimum ACL:

     chacl u::rwx,g::r-x,o::r-- file

   The  file  ACL  is  set  so that the file's owner has "rwx", the file's
   group has read and execute, and others have read  only  access  to  the

   An ACL that is not a minimum ACL, that is, one that specifies a user or
   group other than the file's owner or owner's group, must contain a mask

     chacl u::rwx,g::r-x,o::r--,u:bob:r--,m::r-x file1 file2

   To  set  the  default  and  access  ACLs on newdir to be the same as on
   olddir, you could type:

     chacl -b `chacl -l olddir | \
         sed -e 's/.*\[//' -e 's#/# #' -e 's/]$//'` newdir


   chacl can replace the existing ACL.  To add or delete entries, you must
   first  do  chacl -l to get the existing ACL, and use the output to form
   the arguments to chacl.

   Changing the permission bits of a file will change the file access  ACL
   settings  (see  chmod(1)).   However,  file  creation  mode  masks (see
   umask(1)) will not affect the access  ACL  settings  of  files  created
   using directory default ACLs.

   ACLs  are  filesystem  extended  attributes and hence are not typically
   archived or restored using the conventional archiving  utilities.   See
   attr(5)   for  more  information  about  extended  attributes  and  see
   xfsdump(8) for a method of backing them up under XFS.


   getfacl(1), setfacl(1), chmod(1), umask(1),  acl_from_text(3),  acl(5),


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.