1.16. Element shell

1.16. Element `shell`
	1. Reference

1.16. Element `shell`

<shell
  command = Shell command
  platform = (Unix | Windows | Mac | GenericUnix)
/>

Executes specified command using native shell: cmd.exe on Windows and /bin/sh on Unix (Mac OS X is considered to be a Unix platform).

The current working directory of the native shell is the temporary directory created for the execution of the process-command (%W, see below).

Specified command may reference helper applications declared using the Preferences dialog box, Helper Applications section.

If the platform attribute is not specified, the shell command is executed whatever is the platform running XXE.

If the platform attribute is specified, the shell command is executed only if the platform running XXE matches the value of this attribute:

Windows: Any version of Windows.
Mac: Mac OS X.
GenericUnix: A Unix which is not Mac OS X (Linux, Solaris, etc).
Unix: GenericUnix or Mac.

This applies to the shell element of a process command as well as to the run and start commands.

Instead of containing substring "notepad foo.txt", a command line, interpreted by cmd.exe on Windows and /bin/sh on Unix, may contain something like "helper(text/plain) foo.txt" or "helper(txt) foo.txt" or even "helper() foo.txt".

In the above example, substring "helper(spec) path" refers to a helper application declared using the Preferences dialog box, Helper Applications section.

This preferences sheet allows to associate helper applications to file types. In the above example, we assume that plain text files, that is files having MIME type "text/plain" or having a "txt" filename extension, have been associated to helper application "notepad "%F"".

Examples of command lines making use of helper applications:

<command name="run" 
         parameter="helper(text/plain) '%D'"/>

<command name="start" 
         parameter="helper(defaultViewer) '%_'"/>

<shell command="helper(.hhp) htmlhelp.hhp || exit 0"/>

<shell command="helper(application/x-java-help-index) ."/>

In order to use helper applications, a command line must contain substrings having this syntax: "helper(spec) path".

spec

Specifies which helper application to use. It may be:

A MIME type. Example: "text/plain".
A filename extension, with or without a leading ".". Example: ".hhp".
Fixed string "defaultViewer", which is the helper application specified in Preferences dialog box, Helper Applications section, Default viewer field. This default viewer is generally a Web browser.
Empty. In which case, the filename extension of path is used.

path

Must always follow the helper() construct. This absolute or relative filename or URL may be quoted using single or double quotes if it happens to contain whitespace characters.

When a command line contains a "helper(spec) path" substring, this substring is substituted with the corresponding helper application. How this is done is best explained using an example.

Let's suppose the command line is "helper(defaultViewer) 'foo.html'".

Let's suppose the default viewer is specified as: "(mozilla -remote "openURL(%U)" 1> /dev/null 2>&1) || (mozilla "%U" &)".

Single quotes are stripped from path 'foo.html' and each occurrence of %U (or %F) in the helper application is replaced by this path (without any other added value).

This gives: "(mozilla -remote "openURL(foo.html)" 1> /dev/null 2>&1) || (mozilla "foo.html" &)" (which, in this case, cannot work because foo.html is not an absolute URL).


1.15. Element `jar`		1.17. Element `invoke`