strchg(1M) strchg(1M)
NAME
strchg, strconf - change or query stream configuration
SYNOPSIS
module2]...
[ module]
file
DESCRIPTION
The and commands are used to change or query the configuration of the stream associated with the user's standard input. The command pushes
modules on and/or pops modules off the stream. The command queries the configuration of the stream. Only the superuser or owner of a
STREAMS device may alter the configuration of that stream.
strchg Options
The command uses the following options:
pushes modules onto a
stream. The modules are pushable STREAMS modules as defined by module1, module2, and so on. The modules are pushed in
order. That is, module1 is pushed first, module2 is pushed second, etc.
With the option alone, pops the topmost module from the stream.
With the and options, all the modules above the topmost driver are popped.
With the and module options, all modules above but not including module are popped off the stream.
The and options are mutually exclusive.
The user can specify a
file that contains a list of modules representing the desired configuration of the stream. Each module name must
appear on a separate line where the first name represents the topmost module and the last name represents the module
that should be closest to the driver. The command will determine the current configuration of the stream and pop and
push the necessary modules in order to end up with the desired configuration.
The and options are mutually exclusive.
strconf Options
Invoked without any arguments, prints a list of all the modules in the stream as well as the topmost driver. The list is printed in one
name per line where the first name printed is the topmost module on the stream (if one exists) and the last item printed is the name of the
driver.
The command uses the following options:
Only the topmost module (if one exists) is printed.
checks if the named
module is present on the stream. If so, prints the message, and returns zero. If not, prints the message, and returns a
non-zero value.
The and options are mutually exclusive.
Notes
If the user is neither the owner of the stream nor the superuser, the command will fail. If the user does not have read permissions on the
stream and is not the superuser, the command will fail.
If modules are pushed in the wrong order, one could end up with a stream that does not function as expected. For ttys, if the line disci-
pline module is not pushed in the correct place, one could have a terminal that does not respond to any commands.
DIAGNOSTICS
returns zero on success. It prints an error message and returns non-zero status for various error conditions, including usage error, bad
module name, too many modules to push, failure of an on the stream, or failure to open file from the option.
returns zero on success (for the or option, "success" means the named or topmost module is present). It returns a non-zero status if
invoked with the or option and the module is not present. It prints an error message and returns non-zero status for various error condi-
tions, including usage error or failure of an on the stream.
EXAMPLES
The following command pushes the module on the stream associated with the user's standard input:
The following command pops the topmost module from the stream associated with The user must be the owner of this device or be superuser.
If the file, contains the following:
then the command
will configure the user's standard input stream so that the module is pushed over the driver, followed by and closest to the stream head.
The command with no arguments lists the modules and topmost driver on the stream. For a stream that only has the module pushed above the
ports driver, it would produce the following output:
The following command asks if is on the stream:
and produces the following output while returning an exit status of 0:
FILES
NLS catalogs
NLS catalogs
SEE ALSO
streamio(7).
strchg(1M)