--- a/tail.xml	Sun Oct 06 08:22:36 2013 -0400
+++ b/tail.xml	Wed Jan 07 11:10:52 2015 -0500
@@ -1,29 +1,45 @@
-<tool id="tp_tail_tool" name="Select last" version="0.1.1">
+<tool id="tp_tail_tool" name="Select last" version="@BASE_VERSION@.0">
     <description>lines from a dataset (tail)</description>
-    <requirements>
-        <requirement type="package" version="8.21">gnu_coreutils</requirement>
-    </requirements>
+    <macros>
+        <import>macros.xml</import>
+    </macros>
+    <expand macro="requirements" />
+    <version_command>tail --version | head -n 1</version_command>
     <command>
-        tail --lines $count '$input' &gt; '$output'
+<![CDATA[
+        tail
+            --lines $complement$num_lines
+            '$infile'
+        > '$outfile'
+]]>
     </command>
-
     <inputs>
-        <param format="txt" name="input" type="data" label="file to cut" />
-        <param name="count" type="integer" size="5"  value="10" label="Output last X lines" help="" />
+        <param name="infile" format="txt" type="data" label="Text file" />
+        <param name="complement" type="select" label="Operation">
+            <option value="">Keep last lines</option>
+            <option value="+">Keep everything from this line on</option>
+        </param>
+        <param name="num_lines" type="integer" size="5" value="10" 
+            label="Number of lines" help="These will be kept (depending on 'operation'). (--lines)" />
     </inputs>
-
     <outputs>
-        <data format="input" name="output" metadata_source="input"/>
+        <data name="outfile" format="input" metadata_source="infile"/>
     </outputs>
     <tests>
         <test>
-            <param name="count" value="10"/>
             <param name="infile" value="1.bed"/>
-        <output name="out_file1" file="eq-showtail.dat"/>
+            <param name="num_lines" value="10"/>
+            <output name="outfile" file="tail_results1.bed"/>
+        </test>
+        <test>
+            <param name="infile" value="1.bed"/>
+            <param name="num_lines" value="10"/>
+            <param name="complement" value="+"/>
+            <output name="outfile" file="tail_results2.bed"/>
         </test>
     </tests>
     <help>
-
+<![CDATA[
 **What it does**
 
 This tool outputs specified number of lines from the **end** of a dataset
@@ -45,5 +61,7 @@
     chr7    57341   57361   D17003_CTCF_R7  375     +
     chr7    57457   57477   D17003_CTCF_R3  188     +
 
+@REFERENCES@
+]]>
     </help>
 </tool>