Geografic-Information-System/general/g.filename/g.filename.html

<h2>DESCRIPTION</h2>

<em>g.filename</em> is designed for Bourne shell scripts that need to know 
the full file name, including it's path, for mapset elements, like raster,
vector and site maps, region definitions and imagery groups.
<p>The list of element names to search for is not fixed; any subdirectory of the
mapset directory is a valid element name.
<p>However, the user can find the list of standard GRASS GIS element names in
the file <tt>$GISBASE/etc/element_list</tt>. This is the file which
g.remove/g.rename/g.copy use to determine which files need to be
deleted/renamed/copied for a given entity type.

<!-- unused
<h2>OPTIONS</h2>

<h3>Parameters:</h3>

<dl>
<dt><b>element=</b><em>name</em> 

<dd>The name of a GRASS data base element (i.e., directory
within the GRASS mapset location).

<dt><b>mapset=</b><em>name</em> 

<dd>The name of a GRASS data base mapset.  As a
convenience, a single dot (.) can be used to designate the
current mapset.

<dt><b>file=</b><em>name</em> 

<dd>The name of a GRASS data base file.
</dl>
-->
<h2>OUTPUT</h2>

<em>g.filename</em>
writes one line to standard output:

<dl>
<dd>
file='<em>full_file_pathname'</em>
</dl>

The output is a <em>/bin/sh</em> command to set the
variable specified by the file <em>name</em> to the full
UNIX path name for the data base file.  This variable may
be set in the <em>/bin/sh</em> as follows:

<dl>
<dd>
<div class="code"><pre>
eval `g.filename element=name mapset=name file=name`
</pre></div>
</dl>

<h2>NOTES</h2>

This module generates the filename, but does not care if the file (or mapset
or element) exists or not. This feature allows shell scripts to create new data
base files as well as use existing ones.

<p>
If the mapset is the current mapset, <em>g.filename</em>
can automatically create the <em>element</em> specified if it
doesn't already exist when <b>-c</b> flag is used. This makes it easy
to add new files to the data base without having to worry about the
existence of the required data base directories. (This
program will not create a new mapset, however, if that
specified does not currently exist.)

<p>
This module should not be used to create directories which are at the level
of what this module refer to as files, i.e., directory which carries a name
specified by a user (such as vector map directories) should not be created
using this module. Standard library functions coming with any given language
are a more appropriate tool for that.

<p>The program exits with a 0 if everything is ok;  it exits
with a non-zero value if there is an error, in which case
file=<em>'full_file_pathname'</em> is not output.

<h2>SEE ALSO</h2>

<em>
<a href="g.findfile.html">g.findfile</a>,
<a href="g.gisenv.html">g.gisenv</a>
</em>

<h2>AUTHOR</h2>

Michael Shapiro,
U.S.Army Construction Engineering Research Laboratory