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launcher - a one-stop solution for mapping filenames to handlers using MIME
types
launcher [--all ] [--compressed ] [--default ] [--help ] [--nowait ] [--showtypes
] [--type ] [--version ] filenames...
The launcher is intended to be invoked from a commandline or from any
sort of program requiring application file handling facilities. It is a
layer of indirection between any application and the helper applications
required to open a particular file.
The launcher
can be substituted anywhere a helper app would normally be deployed. Simply
construct the commandline necessary to satisfy the behavior expected by
the calling application.
The Launcher uses two methods to determine
the type of files passed in on the commandline and then maps a defined
handler (see below) to that file (or group of files). If more than one
handler is defined for a given file type, a GUI window will be displayed
allowing the user to choose which application to use.
The Launcher's
primary config file (discussed below) may be edited using either a standard
text editor or the GUI configurator which is installed as part of the
Launcher package. This GUI can be called from the commandline as "launcherconfig"
or may be invoked by clicking the third mouse button in the application
selection GUI.
This basic mode of operation may be modified by using
the options defined below when calling the launcher from a commandline.
- --all
- Send all same-type files to the same handler invocation
if the configuration indicates that the handler can open multiple files.
For instance, open all text/plain documents with the same copy of emacs.
Note that not all helper apps support multiple files on their commandlines.
If the defined app does not support multiple files, a separate instance
will be launched for each file, regardless of the state of this flag. This
option may be specified in the launcher.map file as a launcher directive.
(see below)
- --compressed
- Peek inside compressed files to detect primary
type using the file command's "-z" option. Note that this will return the
internal type which will then be mapped to the handlers defined for that
type. If your defined handlers do not read compressed data then this won't
work very well. One option is to map compressed data reading handlers (like
gv) to the compressed types as well as to their primary types. This can
be used implicitly with the provided definition in the launcher mapfile
called "Peek in compressed..." which will recursively call the launcher with
the --compressed option for you.
- --default
- Surpress user queries and just
use the default handler for each type. The default handler is the *first*
one defined on any given type. This option may be specified in the launcher.map
file as a launcher directive. (see below)
- --help
- Print out the usage message.
- --nowait
- Do not wait for each launched application to exit before continuing
or exiting. Off by default. Some applications (i.e. Netscape) will delete
temporary files when the helper app has exited. If the launcher returns
immediately, the file in question may be deleted by the calling application
before the handler has read it. This option may be specified in the launcher.map
file as a launcher directive. (see below)
- --showtypes
- Print the name and
MIME type of each file to stdout and exit without launching any handlers.
This allows the launcher to be used as a generic MIME file typer.
- --type
mimetype
- Force "mimetype" (of the form type/subtype) to the be type for
all files specified on the commandline - bypasses all filetype tests. If
"mimetype" is unrecognized business will proceed as usual.
- --version
- Print
out the version and primary web address.
/etc/mime.types, /etc/magic.mime,
/etc/launcher.map ~/.mime.types, ~/.magic.mime, ~/.launcher.map
The launcher
uses up to three files to determine file type and type/handler mappings.
Personal user files override global system files. Only one mime.types or
magic.mime file, personal or global, need be readable for the launcher
to do its work. One launcher.map file is required.
- mime.types
- The mime.types
file is a file extension to MIME type definition file. A copy should be
included with the launcher distribution. A copy may also be obtained from
the Apache web server distribution. Lines beginning with a "#" are comments.
Entries follow the form:
type/subtype ext [ext] [ext...]
e.g.
image/jpeg jpg jpeg jfif
- magic.mime
- The magic.mime file is a standard "file" command formatted
magic numbers file. Instead of outputting the normal human readable, difficult
to parse text, it returns MIME types when possible. No attempt will be
made to document the format here. A copy should have been included with
the launcher distribution. Other copies may be obtained from the Apache
web server package or the KDE desktop environment package.
- launcher.map
- The launcher.map file is the one launcher-specific config file in the package.
It is designed to be easily parseable by any utility wishing to have access
to the enclosed type/handler mappings. Some of the launcher's commandline
options may also be set in this file. They are differentiated from the
rest of the data so that other utilities parsing this file may safely
ignore them. This mapfile was also designed to overcome some limitations
of the common metamail .mailcap file format. Lines beginning with a "#"
are comments. All other entries begin with a keyword directive, and all
otherwise unrecognized lines will be ignored by the launcher. All entries
must appear one-per line with NO breaks within records. In the section below,
a "\" is used to escape newlines for readability, but this is NOT NOT NOT
a supported option inside the config file. the launcher.map file may be
edited with a text editor or the "launcherconfig" GUI which is part of
the Launcher distribution.
<directive> <option> <boolean value>
e.g.
launcher nowait 1
- See the options section of this manpage for which options
- are supported
in the config file. The name used in the config file is identical to the
long option name on the commandline, but without the switch prefix "--".
<directive> <macroname> <multiplefileflag> <prettyname> \
<handler definition>
e.g.
handler xv 1 "XV" xv -8 -owncmap %s
handler netscape_rf 0 "Netscape file" netscape3 -remote \
openFile(%s)
The character sequence "%s"
- will be replaced with the
- filename(s).
Similarly, "%d" will be replaced with the parent directory of "%s". Fields
with embedded spaces or tabs MUST be quoted. The multiplefileflag field
indicates whether or not the application will accept more than one filename
on the commandline.
<directive> <mimetype> <handlermacro>
e.g.
map text/Makefile emacs
map text/Makefile make
map text/plain emacs jmacs gxedit xedit printtofile make
Multiple mappings may be defined for each type.
- The FIRST
- type defined
for each type is the default. Multiple mappings may be spread across different
entries or be strung together on a single line. */* is the default handler
for unrecognized types. Defining a handler for */* will prevent the hanlder
disambiguation GUI from being displayed in favor of the default handler.
Wildcard type handlers such as image/* are not yet implemented.
Ethan Gold <etgold at thaumaturgy dot net>
http://thaumaturgy.net/~etgold/software/launcher/
Launcher version 0.85 May 31, 1999
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