strchg(1)                                                         strchg(1)

NAME
     strchg - change stream configuration

SYNOPSIS
     strchg -h module1[,module2...]                                Format 1

     strchg -p[ option]                                            Format 2

     strchg -f file                                                Format 3

DESCRIPTION
     strchg is used to alter the configuration of the stream associated
     with the user's standard input. strchg pushes modules on and/or pops
     modules off the stream. Only the system administrator or the owner of
     a device may alter the configuration of the associated stream. The
     command will fail if run by any other user or if the the user does not
     have read permission on the stream and does not have system adminis-
     trator privileges.

     If you push the modules for a stream in the wrong order, you may find
     that the stream does not function as you expect. For example, if the
     line discipline module is not pushed in the correct place for a termi-
     nal, you may find that your terminal no longer responds to any input.

   Format 1: Pushing modules onto a stream

     strchg -h module1[,module2...]

     You can specify the names of one or more pushable streams modules as
     arguments. These modules are pushed (activated) in the given order,
     i.e. module1 is pushed first, module2 is pushed second, etc. The
     module names must be separated by commas. There must be no spaces
     within the module list.

   Format 2: Popping modules off the stream

     strchg -p[ option]

     If no option is specified with -p, strchg pops the topmost module from
     the stream (deactivates it).

     -a   If you specify -a together with -p, all the modules above the
          topmost driver are popped. The -a option may only be specified
          together with -p, and not in combination with -u.

     -u module
          All modules above but not including module are popped off the
          stream. The -u option may only be specified together with -p, and
          not in combination with -a.

   Format 3: Defining a stream configuration




Page 1                       Reliant UNIX 5.44                Printed 11/98

strchg(1)                                                         strchg(1)

     strchg -f file

     file contains a list of modules representing the required configura-
     tion of the stream. Each module name must appear on a separate line,
     with the first line containing the name of the topmost module and the
     last line the name of the lowest one, i.e. the module that should be
     closest to the driver. strchg determines the current configuration of
     the stream and pops and pushes the necessary modules in order until
     the chosen configuration is achieved.

EXAMPLES
     Example 1

     The following command pushes the module ldterm on the stream associ-
     ated with your standard input:

     $ strchg -h ldterm

     Example 2

     The following command pops the topmost module from the stream associ-
     ated with /dev/term/24. You must be the owner of this device or have
     system administrator privileges to run this command:

     $ strchg -p </dev/term/24

     Example 3

     If the file conf contains the following three lines:

     compat
     ldterm
     ptem

     and you run the command:

     $ strchg -f conf

     strchg will configure your standard input stream with the module ptem
     pushed directly over the driver, followed by the module ldterm above
     it, and with the module compat as the topmost module closest to the
     stream head.

SEE ALSO
     strconf(1), streamio(7).









Page 2                       Reliant UNIX 5.44                Printed 11/98