| CmdLine(3pm) | User Contributed Perl Documentation | CmdLine(3pm) |
Tk::CmdLine - Process standard X11 command line options and set initial resources
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 ] );
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"().
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.
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. $"HOME"/<CLASS>). The Tk::CmdLine functionality for setting initial resources concerns itself with the latter two.
Resource files contain data lines of the form <pattern>:<value>. They may also contain blank lines and comment lines (denoted by a ! character as the first non-blank character). Refer to option for a description of <pattern>:<value>.
Tk::CmdLine::SetArguments([@argument])
The X11 options may be specified using a single dash - as per the X11 convention, or using two dashes -- as per the POSIX standard (e.g. -geometry 100x100, -geometry 100x100 or -geometry=100x100). The options may be interspersed with other options or arguments. A -- by itself terminates option processing.
By default, command line options are extracted from @ARGV the first time a MainWindow is created. The Tk::MainWindow constructor indirectly invokes "SetArguments"() to do this.
Tk::CmdLine::cget([$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
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.
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.
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.
use Tk;
# <Process @ARGV - ignoring all X11-specific options>
my $mw = MainWindow->new();
MainLoop();
use Tk;
Tk::CmdLine::SetArguments(); # Tk::CmdLine->SetArguments() works too
# <Process @ARGV - not worrying about X11-specific options>
my $mw = MainWindow->new();
MainLoop();
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();
use Tk;
Tk::CmdLine::SetArguments();
# <Process @ARGV - not worrying about X11-specific options>
Tk::CmdLine::LoadResources();
my $mw = MainWindow->new();
MainLoop();
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();
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();
MainWindow option
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.
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.
| 2023-03-23 | perl v5.36.0 |