This XQuery Module provides functions for executing system commands from XQuery.
Conventions
All functions in this module are assigned to the http://basex.org/modules/proc
namespace, which is statically bound to the proc
prefix.
All errors are assigned to the http://basex.org/errors
namespace, which is statically bound to the bxerr
prefix.
Functions
proc:system
Template:Mark encoding
option moved to options argument, timeout
and dir
options added.
Signatures
|
proc:system($cmd as xs:string) as xs:string
proc:system($cmd as xs:string, $args as xs:string*) as xs:string
proc:system($cmd as xs:string, $args as xs:string*, $options as map(xs:string, xs:string)) as xs:string
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Summary
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Executes the specified command in a separate process and returns the result as string. $cmd is the name of the command, arguments to the command may be specified via $args . The $options parameter contains process options:
encoding : convert result to the specified encoding. If no encoding is supplied, the system’s default encoding is used.
timeout : abort process execution after the specified number of seconds.
dir : process command in the specified directory.
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Errors
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BXPRnnnn : If the command results in an error, an XQuery error will be raised. Its code will consist of the letters BXPR and four digits with the command’s exit code.
BXPR9999 : the specified encoding does not exist or is not supported.
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Examples
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proc:system('date') returns the current date on a Linux system.
- The following example returns "Command not found", if the command "xyz" cannot be located or executed:
try {
proc:system('xyz')
} catch bxerr:BXPR0002 {
'Command not found.'
}
|
proc:execute
Template:Mark encoding
option moved to options argument, timeout
and dir
options added.
Signatures
|
proc:execute($cmd as xs:string) as element(result)
proc:execute($cmd as xs:string, $args as xs:string*) as element(result)
proc:execute($cmd as xs:string, $args as xs:string*, $options as map(xs:string, xs:string)) as element(result)
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Summary
|
Executes the specified command in a separate process and returns the result as element. $cmd is the name of the command, and arguments to the command may be specified via $args .The $options parameter contains process options:
encoding : convert result to the specified encoding. If no encoding is supplied, the system’s default encoding is used.
timeout : abort process execution after the specified number of seconds.
dir : process command in the specified directory.
A result has the following structure:
<result>
<output>...result output...</output>
<error>...error output...</error>
<code>0</code>
</result>
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Errors
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BXPR9999 : the specified encoding does not exist or is not supported.
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Examples
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proc:execute('dir', '\') returns the files of the root directory of a Windows system.
proc:execute('ls', ('-l', '-a')) executes the ls -la command on Unix systems.
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proc:property
Signatures
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proc:property($name as xs:string) as xs:string?
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Summary
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Returns the system property, specified by $name , or a context parameter of the web.xml file with that name (see Web Applications). An empty sequence is returned if the property does not exist. For environment variables of the operating system, please use fn:environment-variable.
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Examples
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map:merge(proc:property-names() ! map:entry(., proc:property(.))) returns a map with all system properties.
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proc:property-names
Signatures
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proc:property-names() as xs:string*
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Summary
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Returns the names of all Java system properties and context parameters of the web.xml file (see Web Applications). For environment variables of the operating system, please use fn:available-environment-variables.
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Examples
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proc:property('java.runtime.version') returns the version of the Java runtime engine.
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Errors
Code
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Description
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BXPR9999
|
The specified encoding does not exist or is not supported.
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Changelog
- Version 8.6
- Updated: proc:system, proc:exec:
encoding
option moved to options argument, timeout
and dir
options added.
- Version 8.3
The module was introduced with Version 7.3.