# Options for process:execute The eXistdb process module enables admin users to execute system command on the maschine where eXist is running. The process:execute command receives two parameters, the command to execute and optional a list of options. These options are * workingDir * 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 The workingDir parameter is used to specify the directory in which the command is executed. In this sample the workingDir is 'etc', if you don't specify a directory the eXistdb home directory is used as workingDir parameter. ```xquery let $options := \<option> \<workingDir>/etc\</workingDir> \</option> return process:execute(("ls","-l"),$options) ``` ### Result Lists the files in the directory '/etc' in long format (-l) ## Environment Variables ```xquery let $options := \<option> \<environment> \<env name="DATA" value="/path/to/data"/> \</environment> \</option> 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> 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'.