Changes

This [[Module Library|XQuery Module]] provides functions for executing system commands from XQuery.  =Conventions= All functions and errors in this module are introduced with the {{Mono|proc:}} prefix, which is linked assigned to the statically declared {{Mono|<code><nowiki>http://basex.org/modules/proc</nowiki></code> namespace, which is statically bound to the {{Code|proc}} namespaceprefix.<br/>

 {|width='100%'|-| valign='"top' "| width='90120' | '''SignaturesSignature'''|{{Mono|<bpre>proc:system</b>( $cmd command as xs:string) , $arguments as xs:string}}<br/>{{Mono|<b>proc* :system</b>= ($cmd as xs:string), $args options as xsmap(*)? :string*= map { }) as xs:string}}</pre>|-| valign='"top' "| '''Summary'''|Executes a {{Code|$command}} with the specified command {{Code|$arguments}} in a separate process and returns the result as a string. The {{Code|$options}} parameter contains process options:* {{Code|encoding}}: convert result to the specified encoding. If no encoding is supplied, the system’s default encoding is used.* {{Code|timeout}}: abort process execution after the specified number of seconds.* {{Code|dir}}: process command in the specified directory.* {{Code|input}}: standard stringinput ({{Code|stdin}}) to be passed on to the command.|- valign="top"|'''Errors'''|{{Error|encoding|#Error}} the specified encoding does not exist or is not supported.<br/>{{Error|timeout|#Error}} the specified timeout was exceeded.<br/>{{Error|error|#Error}} the command could not be executed, or an I/O exception was raised.<br/>{{Error|code....|#Error}} If the command results in commands returns an errorexit code different to 0, an XQuery exception error will be thrownraised. Its error code will consist of the letters {{MonoCode|PROCcode}} and four digits with the command’s exit code.<br/>Additional command arguments may be specified via {{Mono|$args}}.|-| valign='"top' "| '''Examples'''

* {{MonoCode|proc:system('date')}} returns the current date on a Linux system.* Analyses the given input and counts the number of lines, words and characters (provided that {{Code|wc}} is available on the system):<pre lang='xquery'>proc:system( 'wc', (), map { 'input': 'A B' || out:nl() || 'C' })</pre>* The following example returns "Command “Command not found", if found” (unless {{Code|xyz}} is a valid command on the command "xyz" cannot be located or executedsystem):<pre classlang="brush:'xquery"'>

} catch PROC0001 proc:error { 'Command not found.: '|| $err:description

 {|width='100%'|-| valign='"top' "| width='90120' | '''SignaturesSignature'''|{{Mono|<bpre>proc:execute</b>( $cmd command as xs:string) as element(result)}}<br/>{{Mono|<b>proc:execute</b>(, $cmd arguments as xs:string* := (), $args options as xsmap(*)? :string*= map { }) as element(result)}}</pre>|-| valign='"top' "| '''Summary'''|Executes a {{Code|$command}} with the specified command {{Code|$arguments}} in a separate process and returns the result as an element:* The same {{Code|$options}} are allowed as for {{Function||proc:system}}.<br/>Additional command arguments may * Instead of the {{Code|proc:error}} error, the error message and process code will be specified via assigned to the returned elements.* Instead of the {{MonoCode|$argsproc:code....}}error, the error message will be assigned to the returned element (no process code will be returned).<br/>A The result has the following structure:<br/><pre classlang="brush:xml">

<output>...resultoutput...</output> <error>...error message...</error> <code>0...process code...</code>

|-valign="top"|'''Errors'''|{{Error|encoding|#Error}} the specified encoding does not exist or is not supported.<br/>{{Error|timeout|#Error}} the specified timeout was exceeded.|- valign="top"| '''Examples'''|* {{Code|proc:execute('dir', '\')}} returns the files of the root directory of a Windows system.* {{Code|proc:execute('ls', ('-l', '-a'))}} executes the {{Code|ls -la}} command on Unix systems.|} ==proc:fork== {| width='100%'|- valign="top"| width='120' | '''Signature'''|<pre>proc:fork( $command as xs:string, $arguments as xs:string* := (), $options as map(*)? := map { }) as element(result)</pre>| - valign="top"| '''Summary'''|Executes a {{Code|$command}} with the specified {{Code|$arguments}} in a separate process and ignores the result. The same {{Code|$options}} are allowed as for {{Function||proc:system}} with the encoding being ignored.|- valign="top"|''' Errors'''|{{Error|encoding|#Error}} the specified encoding does not exist or is not supported.|- valign="top"| '''Examples'''|* {{Code|proc:fork('sleep', '5')}}: sleep for 5 seconds (no one should notice).|} ==proc:property== {| width='100%'|- valign="top"| width='120' | '''Signature'''|<pre>proc:property( $name as xs:string) as xs:string?</pre>|- valign="top"| '''Summary'''|Returns the system property, specified by {{Code|$name}}, or a context parameter of the {{Code|web.xml}} file with that name (see [[Web_Application#Configuration|Web Applications]]). An empty sequence is returned if the property does not exist. For environment variables of the operating system, please use [https://www.w3.org/TR/xpath-functions-30/#func-environment-variable fn:environment-variable]. |- valign="top"| '''Examples'''|* {{Code|proc:property('java.class.path')}} returns the full user class path.* {{Code|map:merge(proc:property-names() ! map:entry(., proc:property(.)))}} returns a map with all system properties.|} ==proc:property-names== {| width='100%'|- valign="top"| width='120' | '''Signature'''|<pre>proc:property-names() as xs:string*</pre>|- valign="top"| '''Summary'''|Returns the names of all Java system properties and context parameters of the {{Code|web.xml}} file (see [[Web_Application#Configuration|Web Applications]]). For environment variables of the operating system, please use [https://www.w3.org/TR/xpath-functions-30/#func-available-environment-variables fn:available-environment-variables]. |- valign="top"| '''Examples'''

* {{MonoCode|proc:executeproperty('dir', '\java.runtime.version')}} returns the root directory on version of the Java runtime engine.|} =Errors= {| class="wikitable" width="100%"! width="110"|Code|Description|- valign="top"|{{Code|code...}}|The result of a Windows systemcommand call with an exit code different to 0.|- valign="top"|{{Code|code9999}}|A command could not be executed.|- valign="top"|{{Code|encoding}}|The specified encoding does not exist or is not supported.|- valign="top"|{{Code|timeout}}|The specified timeout was exceeded.

The ;Version 9.0 * Added: {{Function||proc:fork}}* Updated: error codes; errors now use the module was introduced with namespace* Updated: new {{Code|input}} option; revised error handling ;Version8.6 * Updated: {{Function||proc:system}}, {{Function||proc:exec}}: {{Code|7encoding}} option moved to options argument, {{Code|timeout}} and {{Code|dir}} options added.2 ;Version 8.23 * Added: {{Function||proc:property}}, {{Function||proc:property-names}}. The module was introduced with Version 7.3.