Manual Pages for UNIX Operating System command usage for man readonly

User Commands                                         readonly(1)



NAME
     readonly - shell built-in function to protect the  value  of
     the given variable from reassignment

SYNOPSIS
  sh
     readonly [name]...


  ksh
     **readonly [name [= value]]...


     **readonly -p


  ksh93
     ++readonly [-p] [name [= value]]...


DESCRIPTION
  sh
     The given names are marked readonly and the  values  of  the
     these  names may not be changed by subsequent assignment. If
     no arguments are given, a list  of  all  readonly  names  is
     printed.

  ksh
     The given names are marked readonly and these  names  cannot
     be changed by subsequent assignment.


     When -p is specified, readonly writes to the standard output
     the names and values of all read-only variables, in the fol-
     lowing format:

       "readonly %s=%s\n", name, value




     if name is set, and:

       "readonly $s\n", name




     if name is unset.






SunOS 5.11           Last change: 2 Nov 2007                    1






User Commands                                         readonly(1)



     The shell formats the output, including the  proper  use  of
     quoting,  so that it is suitable for reinput to the shell as
     commands  that  achieve  the   same   value   and   readonly
     attribute-setting  results  in a shell execution environment
     in which:

         1.   Variables with values set at  the  time  they  were
              output do not have the readonly attribute set.

         2.   Variables that were unset at  the  time  they  were
              output do not have a value at the time at which the
              saved output is re-input to the shell.


     On this manual page, ksh(1) commands that  are  preceded  by
     one  or two ** (asterisks) are treated specially in the fol-
     lowing ways:

         1.   Variable assignment  lists  preceding  the  command
              remain in effect when the command completes.

         2.   I/O  redirections  are  processed  after   variable
              assignments.

         3.   Errors cause a script that contains them to abort.

         4.   Words, following a command preceded by ** that  are
              in   the  format  of  a  variable  assignment,  are
              expanded with the same rules as a variable  assign-
              ment.  This  means  that tilde substitution is per-
              formed after the = sign and word splitting and file
              name generation are not performed.

  ksh93
     readonly sets the readonly attribute on each  of  the  vari-
     ables  specified  by  name  which prevents their values from
     being changed. If =value is specified, the variable name  is
     set to value before the variable is made readonly.


     If no names are specified then the names and values  of  all
     readonly variables are written to standard output.


     readonly is built-in to the shell as a  declaration  command
     so  that field splitting and pathname expansion are not per-
     formed on the arguments. Tilde expansion occurs on value.

     -p    Causes the output to be in a form of readonly commands
           that can be used as input to the shell to recreate the
           current set of readonly variables.




SunOS 5.11           Last change: 2 Nov 2007                    2






User Commands                                         readonly(1)



     On this manual page, ksh93(1) commands that are preceded  by
     one  or two + symbols are treated specially in the following
     ways:

         1.   Variable assignment  lists  preceding  the  command
              remain in effect when the command completes.

         2.   I/O  redirections  are  processed  after   variable
              assignments.

         3.   Errors cause a script that contains them to abort.

         4.   They are not valid function names.

         5.   Words, following a command preceded by ++ that  are
              in   the  format  of  a  variable  assignment,  are
              expanded with the same rules as a variable  assign-
              ment.  This  means  that tilde substitution is per-
              formed after the = sign  and  field  splitting  and
              file name generation are not performed.

EXIT STATUS
  ksh93
     The following exit values are returned:

     0     Successful completion.


     >0    An error occurred.


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



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcs                      |
    |_____________________________|_____________________________|


SEE ALSO
     ksh(1), ksh93(1), sh(1), typeset(1), attributes(5)









SunOS 5.11           Last change: 2 Nov 2007                    3