launcher(1)

NAME

launcher - a one-stop solution for mapping filenames to

handlers using MIME types

SYNOPSIS

launcher   [--all]   [--compressed]  [--default]  [--help]
[--nowait] [--showtypes] [--type] [--version] filenames...

DESCRIPTION

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.

GENERAL OPERATION

The launcher can be substituted anywhere a helper app

would normally be deployed. Simply construct the commandline nec

essary to satisfy the behavior expected by the calling applica

tion.

The Launcher uses two methods to determine the type of

files passed in on the commandline and then maps a defined han

dler (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 configu

rator 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 command

line.

OPTIONS

--all Send all same-type files to the same handler invo

cation 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 de

fined for that type. If your defined handlers do not read com

pressed 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 implic

itly 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 han

dler for each type. The default handler is the *first* one de

fined 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 launch

er.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 pro

ceed as usual.

--version

Print out the version and primary web address.

FILES

/etc/mime.types, /usr/share/misc/magic, /etc/magic,

/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. En

tries follow the form:

type/subtype ext [ext] [ext...]
e.g.
image/jpeg jpg jpeg jfif

magic The magic file is a standard "file" command format

ted 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/han

dler mappings. Some of the launcher's commandline options may al

so be set in this file. They are differentiated from the rest of

the data so that other utilities parsing this file may safely ig

nore them. This mapfile was also designed to overcome some limi

tations of the common metamail .mailcap file format. Lines be

ginning 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 "

Launcher options are set as follows:

<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 command

line, but without the switch prefix "--".

Handler/helper application definitions are set as

follows:

<directive> <macroname> <multiplefileflag> <pretty

name> <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 command

line.

Type/Handler mapping entries are set as follows:

<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 map

pings may be spread across different entries or be strung togeth

er on a single line. */* is the default handler for unrecognized

types. Defining a handler for */* will prevent the hanlder disam

biguation GUI from being displayed in favor of the default han

dler. Wildcard type handlers such as image/* are not yet imple

mented.

AUTHOR

Ethan Gold <etgold@cs.columbia.edu>
http://www.cs.columbia.edu/~etgold/software/launcher/

Launcher version 0.85 May 31, 1999

launch

er(1)