Bureaucrats, editor, reviewer, Administrators
13,550
edits
Changes
Jump to navigation
Jump to search
{{Mark|Updated with Version 8.6:}} third argument replaced with options argument.
{{Mark|Updated with Version 8.6:}} third argument replaced with options argument.
→proc:property
=Conventions=
All functions and errors in this module are assigned to the <code><nowiki>http://basex.org/modules/proc</nowiki></code> namespace, which is statically bound to the {{Code|proc}} prefix.<br/>All errors are assigned to the <code><nowiki>http://basex.org/errors</nowiki></code> namespace, which is statically bound to the {{Code|bxerr}} prefix.
=Functions=
==proc:system==
{| width='100%'
| '''Summary'''
|Executes the specified command in a separate process and returns the result as string. {{Code|$cmd}} is the name of the command, arguments to the command may be specified via {{Code|$args}}. 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}}: query abort process execution will be interrupted after the specified number of seconds.* {{Code|dir}}: process command in the specified directory.* {{Code|input}}: standard string input ({{Code|stdin}}) to be passed on to the command.
|-
|'''Errors'''
|{{Error|BXPRnnnnencoding|#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 error will be raised. Its code will consist of the letters {{Code|BXPRcode}} and four digits with the command’s exit code.<br/>{{Error|BXPR9999|#Error}} the specified encoding does not exist or is not supported.
|-
| '''Examples'''
|
* {{Code|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 class="brush: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 class="brush:xquery">
try {
proc:system('xyz')
} catch bxerrproc:BXPR0002 error { 'Command not found.: '|| $err:description
}
</pre>
==proc:execute==
{| width='100%'
|-
| '''Summary'''
|Executes the specified command in a separate process and returns the result as element. :* {{Code|$cmd}} is the name of the command, and arguments to the command may be specified via {{Code|$args}}.* The same {{Code|$options}} parameter contains process optionsare allowed as for [[#proc:system|proc:system]].* Instead of the {{Code|$encodingproc:error}}: convert result error, the error message and process code will be assigned to the specified encoding. If no encoding is supplied, the system’s default encoding is usedreturned elements.* Instead of the {{Code|timeoutproc:code....}}: query execution error, the error message will be interrupted after assigned to the specified number of secondsreturned element (no process code will be returned).A The result has the following structure:
<pre class="brush:xml">
<result>
<output>...result output...</output> <error>...error outputmessage...</error> <code>0...process code...</code>
</result>
</pre>
|-
|'''Errors'''
|{{Error|BXPR9999encoding|#Error}} the specified encoding does not exist or is not supported.<br/>{{Error|timeout|#Error}} the specified timeout was exceeded.
|-
| '''Examples'''
* {{Code|proc:execute('dir', '\')}} returns the files of the root directory of a Windows system.
* {{Code|proc:execute('ls', ('-l', '-a'))}} executes the {{Code|ls -la}} command on Unix systems.
|}
==proc:fork==
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|proc:fork|$cmd as xs:string|element(result)}}<br/>{{Func|proc:fork|$cmd as xs:string, $args as xs:string*|element(result)}}<br/>{{Func|proc:fork|$cmd as xs:string, $args as xs:string*, $options as map(xs:string, xs:string)|element(result)}}
|-
| '''Summary'''
|Executes the specified command and ignores the result. {{Code|$cmd}} is the name of the command, and arguments to the command may be specified via {{Code|$args}}. The same {{Code|$options}} are allowed as for [[#proc:system|proc:system]] (but the encoding will be ignored).
|-
|'''Errors'''
|{{Error|encoding|#Error}} the specified encoding does not exist or is not supported.
|-
| '''Examples'''
|
* {{Code|proc:fork('sleep', '5')}}: sleep for 5 seconds (no one should notice).
|}
| '''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.
|}
|Description
|-
|{{Code|BXPR9999code...}}|The result of a command call with an exit code different to 0.|-|{{Code|code9999}}|A command could not be executed.|-|{{Code|encoding}}
|The specified encoding does not exist or is not supported.
|-
|{{Code|timeout}}
|The specified timeout was exceeded.
|}
=Changelog=
;Version 9.0
* Added: [[#proc:fork|proc:fork]]
* Updated: error codes; errors now use the module namespace
* Updated: new {{Code|input}} option; revised error handling
;Version 8.6
* Updated: [[#proc:system|proc:system]], [[#proc:exec|proc:exec]]: third {{Code|encoding}} option moved to options argument replaced with , {{Code|timeout}} and {{Code|dir}} options argumentadded.
;Version 8.3
