NAME¶
Tk::CmdLine - Process standard X11 command line options and set initial
resources
SYNOPSIS¶
Tk::CmdLine::SetArguments([@argument]);
my $value = Tk::CmdLine::cget([$option]);
Tk::CmdLine::SetResources((\@resource | $resource) [, $priority]);
Tk::CmdLine::LoadResources(
[ -symbol => $symbol ]
[ -file => $fileSpec ]
[ -priority => $priority ]
[ -echo => $fileHandle ] );
DESCRIPTION¶
Process standard X11 command line options and set initial resources.
The X11R5 man page for X11 says: "Most X programs attempt to use the same
names for command line options and arguments. All applications written with
the X Toolkit Intrinsics automatically accept the following options:
...". This module processes these command line options for perl/Tk
applications using the "SetArguments"() function.
This module can optionally be used to load initial resources explicitly via
function "SetResources"(), or from specified files (default: the
standard X11 application-specific resource files) via function
"LoadResources"().
Command Line Options¶
- -background Color | -bg
Color
- Specifies the color to be used for the window
background.
- -class Class
- Specifies the class under which resources for the
application should be found. This option is useful in shell aliases to
distinguish between invocations of an application, without resorting to
creating links to alter the executable file name.
- -display Display | -screen
Display
- Specifies the name of the X server to be used.
- -font Font | -fn Font
- Specifies the font to be used for displaying text.
- -foreground Color | -fg
Color
- Specifies the color to be used for text or graphics.
- -geometry Geometry
- Specifies the initial size and location of the first
MainWindow.
- -iconic
- Indicates that the user would prefer that the application's
windows initially not be visible as if the windows had been immediately
iconified by the user. Window managers may choose not to honor the
application's request.
- -motif
- Specifies that the application should adhere as closely as
possible to Motif look-and-feel standards. For example, active elements
such as buttons and scrollbar sliders will not change color when the
pointer passes over them.
- -name Name
- Specifies the name under which resources for the
application should be found. This option is useful in shell aliases to
distinguish between invocations of an application, without resorting to
creating links to alter the executable file name.
- -synchronous
- Indicates that requests to the X server should be sent
synchronously, instead of asynchronously. Since Xlib normally buffers
requests to the server, errors do do not necessarily get reported
immediately after they occur. This option turns off the buffering so that
the application can be debugged. It should never be used with a working
program.
- -title TitleString
- This option specifies the title to be used for this window.
This information is sometimes used by a window manager to provide some
sort of header identifying the window.
- -xrm ResourceString
- Specifies a resource pattern and value to override any
defaults. It is also very useful for setting resources that do not have
explicit command line arguments.
The ResourceString is of the form
<pattern>:<value>, that is (the first) ':' is
used to determine which part is pattern and which part is value. The (<
pattern>, <value>) pair is entered into the options
database with optionAdd (for each MainWindow configured), with
interactive priority.
Initial Resources¶
There are several mechanism for initializing the resource database to be used by
an X11 application. Resources may be defined in a $"HOME"/.Xdefaults
file, a system application defaults file (e.g. /usr/lib/X11/app-defaults/<
CLASS>), or a user application defaults file (e.g.
$"HOME"/<
CLASS>). The Tk::CmdLine functionality for
setting initial resources concerns itself with the latter two.
Resource files contain data lines of the form <
pattern>:<
value>. They may also contain blank lines and
comment lines (denoted by a ! character as the first non-blank character).
Refer to option for a description of <
pattern>:<
value>.
- System Application Defaults Files
- System application defaults files may be specified via
environment variable $"XFILESEARCHPATH" which, if set, contains
a list of file patterns (joined using the OS-dependent path delimiter,
e.g. colon on UNIX).
- User Application Defaults Files
- User application defaults files may be specified via
environment variables $"XUSERFILESEARCHPATH",
$"XAPPLRESDIR" or $"HOME".
METHODS¶
- SetArguments -
Tk::CmdLine::SetArguments([@argument])
- Extract the X11 options contained in a specified array
(@ARGV by default).
Tk::CmdLine::SetArguments([@argument])
The X11 options may be specified using a single dash - as per the X11
convention, or using two dashes -- as per the POSIX standard (e.g.
-geometry 100x100, -geometry 100x100 or
-geometry= 100x100). The options may be interspersed with
other options or arguments. A -- by itself terminates option
processing.
By default, command line options are extracted from @ARGV the first time a
MainWindow is created. The Tk::MainWindow constructor indirectly invokes
"SetArguments"() to do this.
- GetArguments -
Tk::CmdLine::GetArguments()
- Get a list of the X11 options that have been processed by
"SetArguments"(). ("GetArguments"() first invokes
"SetArguments"() if it has not already been invoked.)
- cget - Tk::CmdLine::cget([$option])
- Get the value of a configuration option specified via
"SetArguments"(). ("cget"() first invokes
"SetArguments"() if it has not already been invoked.)
Tk::CmdLine::cget([$option])
The valid options are: -class, -name, -screen and
-title. If no option is specified, -class is implied.
A typical use of "cget"() might be to obtain the application class
in order to define the name of a resource file to be loaded in via
"LoadResources"().
my $class = Tk::CmdLine::cget(); # process command line and return class
- SetResources - Tk::CmdLine::SetResources((\@resource
| $resource) [, $priority])
- Set the initial resources.
Tk::CmdLine::SetResources((\@resource | $resource) [, $priority])
A single resource may be specified using a string of the form '<
pattern>:< value>'. Multiple resources may be
specified by passing an array reference whose elements are either strings
of the above form, and/or anonymous arrays of the form [ <
pattern>, < value> ]. The optional second argument
specifies the priority, as defined in option, to be associated with the
resources (default: userDefault).
Note that "SetResources"() first invokes
"SetArguments"() if it has not already been invoked.
- LoadResources -
Tk::CmdLine::LoadResources([%options])
- Load initial resources from one or more files.
Tk::CmdLine::LoadResources(
[ -symbol => $symbol ]
[ -file => $fileSpec ]
[ -priority => $priority ]
[ -echo => $fileHandle ] );
[ -symbol => $symbol ] specifies the name of an environment
variable that, if set, defines a list of one or more directories and/or
file patterns (joined using the OS-dependent path delimiter, e.g. colon on
UNIX). $"XUSERFILESEARCHPATH" is a special case. If
$"XUSERFILESEARCHPATH" is not set, $"XAPPLRESDIR" is
checked instead. If $"XAPPLRESDIR" is not set, $"HOME"
is checked instead.
An item is identified as a file pattern if it contains one or more
/%[A-Za-z]/ patterns. Only patterns %L,
%T and %N are currently
recognized. All others are replaced with the null string. Pattern
%L is translated into $"LANG". Pattern
%T is translated into app-defaults. Pattern
%N is translated into the application class name.
Each file pattern, after substitutions are applied, is assumed to define a
FileSpec to be examined.
When a directory is specified, FileSpecs <
DIRECTORY>/<LANG>/< CLASS> and <
DIRECTORY>/<CLASS> are defined, in that order.
[ -file => $fileSpec ] specifies a resource file to be loaded in.
The file is silently skipped if if does not exist, or if it is not
readable.
[ -priority => $priority ] specifies the priority, as defined in
option, to be associated with the resources (default: userDefault).
[ -echo => $fileHandle ] may be used to specify that a line should
be printed to the corresponding FileHandle (default: \*STDOUT) everytime a
file is examined / loaded.
If no -symbol or -file options are specified,
"LoadResources"() processes symbol $"XFILESEARCHPATH"
with priority startupFile and $"XUSERFILESEARCHPATH" with
priority userDefault. (Note that $"XFILESEARCHPATH" and
$"XUSERFILESEARCHPATH" are supposed to contain only patterns.
$"XAPPLRESDIR" and $"HOME" are supposed to be a single
directory. "LoadResources"() does not check/care whether this is
the case.)
For each set of FileSpecs, "LoadResources"() examines each
FileSpec to determine if the file exists and is readable. The first file
that meets this criteria is read in and "SetResources"() is
invoked.
Note that "LoadResources"() first invokes
"SetArguments"() if it has not already been invoked.
NOTES¶
This module is an object-oriented module whose methods can be invoked as object
methods, class methods or regular functions. This is accomplished via an
internally-maintained object reference which is created as necessary, and
which always points to the last object used. "SetArguments"(),
"SetResources"() and "LoadResources"() return the object
reference.
EXAMPLES¶
- 1.
- @ARGV is processed by Tk::CmdLine at MainWindow creation.
use Tk;
# <Process @ARGV - ignoring all X11-specific options>
my $mw = MainWindow->new();
MainLoop();
- 2.
- @ARGV is processed by Tk::CmdLine before MainWindow
creation. An @ARGV of (--geometry=100x100 -opt1 a b c -bg red) is equal to
(-opt1 a b c) after "SetArguments"() is invoked.
use Tk;
Tk::CmdLine::SetArguments(); # Tk::CmdLine->SetArguments() works too
# <Process @ARGV - not worrying about X11-specific options>
my $mw = MainWindow->new();
MainLoop();
- 3.
- Just like 2) except that default arguments are loaded
first.
use Tk;
Tk::CmdLine::SetArguments(qw(-name test -iconic));
Tk::CmdLine::SetArguments();
# <Process @ARGV - not worrying about X11-specific options>
my $mw = MainWindow->new();
MainLoop();
- 4.
- @ARGV is processed by Tk::CmdLine before MainWindow
creation. Standard resource files are loaded in before MainWindow
creation.
use Tk;
Tk::CmdLine::SetArguments();
# <Process @ARGV - not worrying about X11-specific options>
Tk::CmdLine::LoadResources();
my $mw = MainWindow->new();
MainLoop();
- 5.
- @ARGV is processed by Tk::CmdLine before MainWindow
creation. Standard resource files are loaded in before MainWindow creation
using non-default priorities.
use Tk;
Tk::CmdLine::SetArguments();
# <Process @ARGV - not worrying about X11-specific options>
Tk::CmdLine::LoadResources(-echo => \*STDOUT,
-priority => 65, -symbol => 'XFILESEARCHPATH' );
Tk::CmdLine::LoadResources(-echo => \*STDOUT,
-priority => 75, -symbol => 'XUSERFILESEARCHPATH' );
my $mw = MainWindow->new();
MainLoop();
- 6.
- @ARGV is processed by Tk::CmdLine before MainWindow
creation. Standard resource files are loaded in before MainWindow
creation. Individual resources are also loaded in before MainWindow
creation.
use Tk;
Tk::CmdLine::SetArguments();
# <Process @ARGV - not worrying about X11-specific options>
Tk::CmdLine::LoadResources();
Tk::CmdLine::SetResources( # set a single resource
'*Button*background: red',
'widgetDefault' );
Tk::CmdLine::SetResources( # set multiple resources
[ '*Button*background: red', '*Button*foreground: blue' ],
'widgetDefault' );
my $mw = MainWindow->new();
MainLoop();
ENVIRONMENT¶
- HOME (optional)
- Home directory which may contain user application defaults
files as $"HOME"/$"LANG"/< CLASS> or
$"HOME"/< CLASS>.
- LANG (optional)
- The current language (default: C).
- XFILESEARCHPATH (optional)
- List of FileSpec patterns (joined using the OS-dependent
path delimiter, e.g. colon on UNIX) used in defining system
application defaults files.
- XUSERFILESEARCHPATH (optional)
- List of FileSpec patterns (joined using the OS-dependent
path delimiter, e.g. colon on UNIX) used in defining user
application defaults files.
- XAPPLRESDIR (optional)
- Directory containing user application defaults files as
$"XAPPLRESDIR"/$"LANG"/< CLASS> or
$"XAPPLRESDIR"/< CLASS>.
SEE ALSO¶
MainWindow option
HISTORY¶
- •
- 1999.03.04 Ben Pavon <ben.pavon@hsc.hac.com>
Rewritten as an object-oriented module.
Allow one to process command line options in a specified array (@ARGV by
default). Eliminate restrictions on the format and location of the options
within the array (previously the X11 options could not be specified in
POSIX format and had to be at the beginning of the array).
Added the "SetResources"() and "LoadResources"()
functions to allow the definition of resources prior to MainWindow
creation.
- •
- 2000.08.31 Ben Pavon <ben.pavon@hsc.hac.com>
Added the "GetArguments"() method which returns the list of
arguments that have been processed by "SetArguments"().
Modified "LoadResources"() to split the symbols using the
OS-dependent path delimiter defined in the Config module.
Modified "LoadResources"() to eliminate a warning message when
processing patterns %l, %C,
%S.