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umask


NAME
     umask - get or set the file mode creation mask

SYNOPSIS
     /usr/bin/umask [-S] [mask]

  sh
     umask [ooo]

  csh
     umask [ooo]

  ksh
     umask [-S] [mask]

DESCRIPTION
     The umask utility sets the file mode creation  mask  of  the
     current  shell  execution environment to the value specified
     by the mask operand. This mask affects the initial value  of
     the  file  permission bits of subsequently created files. If
     umask is called in a subshell or separate utility  execution
     environment, such as one of the following:

     (umask 002)
     nohup umask ...
     find . -exec umask ...

     it does not affect  the  file  mode  creation  mask  of  the
     caller's  environment.  For  this reason, the /usr/bin/umask
     utility cannot be used to change the  umask  in  an  ongoing
     session.  Its usefulness is limited to checking the caller's
     umask. To change the umask of an ongoing  session  you  must
     use one of the shell builtins.

     If the mask operand is  not  specified,  the  umask  utility
     writes  the  value of the invoking process's file mode crea-
     tion mask to standard output.

  sh
     The user file-creation mode mask is set to  ooo.  The  three
     octal  digits  refer  to  read/write/execute permissions for
     owner,  group,  and  other,  respectively   (see   chmod(1),
     chmod(2),  and  umask(2)). The value of each specified digit
     is subtracted from the corresponding ``digit'' specified  by
     the  system  for  the creation of a file (see creat(2)). For
     example, umask 022 removes write permission  for  group  and
     other.  Files  (and  directories) normally created with mode
     777 become mode 755. Files (and  directories)  created  with
     mode 666 become mode 644).

       o  If ooo is omitted, the current value  of  the  mask  is
          printed.

       o  umask is recognized and executed by the shell.

       o  umask can be included in the user's .profile (see  pro-
          file(4))  and invoked at login to automatically set the
          user's permissions on files or directories created.


  csh
     See the description above for  the  Bourne  shell  (sh)umask
     built-in.

  ksh
     The user file-creation mask is set to mask. mask can  either
     be  an  octal  number  or  a  symbolic value as described in
     chmod(1). If a symbolic value is given, the new umask  value
     is the complement of the result of applying mask to the com-
     plement of the previous umask value. If mask is omitted, the
     current value of the mask is printed.

OPTIONS
     The following option is supported:

     -S       Produces symbolic output.



     The default output style is unspecified, but will be  recog-
     nized on a subsequent invocation of umask on the same system
     as a mask operand to restore the previous file mode creation
     mask.

OPERANDS
     The following operand is supported:

     mask     A string specifying  the  new  file  mode  creation
              mask.  The string is treated in the same way as the
              mode operand described in the chmod(1) manual page.

              For a symbolic_mode value, the  new  value  of  the
              file  mode  creation mask is the logical complement
              of the file permission bits  portion  of  the  file
              mode specified by the symbolic_mode string.

              In a symbolic_mode value, the permissions op  char-
              acters  +  and  -  are  interpreted relative to the
              current file mode creation mask. + causes the  bits
              for  the indicated permissions to be cleared in the
              mask. - causes the bits of  the  indicated  permis-
              sions to be set in the mask.

              The interpretation of mode values that specify file
              mode  bits  other  than the file permission bits is
              unspecified.

              The file mode creation mask is set to the resulting
              numeric value.

              The default output of a prior invocation  of  umask
              on  the  same  system  with no operand will also be
              recognized as a mask operand. The use of an operand
              obtained in this way is not obsolescent, even if it
              is an octal number.



OUTPUT
     When the mask operand is not specified,  the  umask  utility
     will  write  a  message to standard output that can later be
     used as a umask mask operand.

     If -S is specified, the message will  be  in  the  following
     format:

     "u=%s,g=%s,o=%s\n", owner permissions, group permissions, \
                             other permissions

     where the three values will be combinations of letters  from
     the  set  {r,  w, x}. The presence of a letter will indicate
     that the corresponding bit is clear in the file  mode  crea-
     tion mask.

     If a mask operand is specified,  there  will  be  no  output
     written to standard output.

EXAMPLES
     Example 1: Using the umask Command

     The examples in this section  refer  to  the  /usr/bin/umask
     utility and the ksh umask builtin.

     Either of the commands:

     umask a=rx,ug+w
     umask 002

     sets the mode mask so that subsequently created  files  have
     their S_IWOTH bit cleared.

     After setting the mode mask with either of  the  above  com-
     mands,  the  umask  command can be used to write the current
     value of the mode mask:

     example$ umask
     0002
     The output format is unspecified, but historical implementa-
     tions use the obsolescent octal integer mode format.

     example$ umask -S
     u=rwx,g=rwx,o=rx

     Either of these outputs can be used as the mask operand to a
     subsequent invocation of the umask utility.

     Assuming the mode mask is set as above, the command:

     umask g-w

     sets the mode mask so that subsequently created  files  have
     their S_IWGRP and S_IWOTH bits cleared.

     The command:

     umask --w

     sets the mode mask so that subsequently created  files  have
     all  their  write bits cleared. Notice that mask operands r,
     w, x, or anything beginning with a hyphen (-), must be  pre-
     ceded by - to keep it from being interpreted as an option.

ENVIRONMENT VARIABLES
     See environ(5) for descriptions of the following environment
     variables  that affect the execution of umask: LANG, LC_ALL,
     LC_COLLATELC_CTYPE, LC_MESSAGES, and NLSPATH.

EXIT STATUS
     The following exit values are returned:

     0        The  file  mode  creation  mask  was   successfully
              changed, or no mask operand was supplied.



     >0       An error occurred.



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:







     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


SEE ALSO
     chmod(1),  csh(1),  ksh(1),   sh(1),   chmod(2),   creat(2),
     umask(2),   profile(4),   attributes(5),  environ(5),  stan-
     dards(5)










Man pages from Solaris 10 Update 8. See docs.sun.com and www.oracle.com for further documentation and Solaris information.
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