Merge pull request #28 from line-o/doc/process-execute

improve process:execute examples

src/main/xar-resources/data/docs/process/execute.md

@@ -6,6 +6,8 @@ The eXistdb process module enables admin users to execute system command on the
 * enviroment
 * stdin
 
+If you want to print environment variables or pass wildcard character to scripts it is necessary to call *sh*, *bash* or *zsh* with the -c option and provide the command as a single third parameter.
+
 
 ## Working Directory
 
@@ -19,10 +21,11 @@ return
 	process:execute(("ls","-l"),$options)
 ```
 ### Result
+
 Lists the files in the directory '/etc' in long format (-l)
 
 
-## Environment Variables 
+## Environment Variables
 
 ```xquery
 let $options := \<option>
@@ -34,24 +37,46 @@ return
 	process:execute(("sh", "-c", "echo $DATA"), $options)
 ```
 
+
 ### Result
+
 Echoes the value of the environment variable $DATA which is '/path/to/data'
 
+## Wildcards / globbing
+
+In order to pass wildcard characters down to the shell-script this must also be done using `sh -c`.
+
+Note: **bash**, **zsh** and **sh** do have the `-c` option.
+
+```xquery
+let $options := \<option>
+                    \<workingDir>/tmp\</workingDir>
+                \</option>
+
+process:execute(("sh", "-c", "ls *.xml"), )
+```
+
+### Result
+
+Lists all files with xml as their file extension.
+
+**NOTE:** `process:execute(("ls", "*.xml"), $options)` returns an error.
 
 ## stdin
 The command executed via process:execute reads the value(s) given as stdin argument(s)
 
 ```xquery
 let $options := \<option>
-				        \<stdin>
-				            \<line>One</line>
-				            \<line>Two</line>
-				        \</stdin>
-				    \</option>
+				    \<stdin>
+				        \<line>One</line>
+				        \<line>Two</line>
+				    \</stdin>
+				\</option>
 
 return 
 	process:execute(("wc", "-l"), $options)   
 ```
 
 ### Result
+
 The Unix command 'wc -l' prints the line count of the given argument (here <stdin>). The result is '2'.