Difference between revisions of "File Module"

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The file module contains extension functions to perform file system related operations, such as listing, reading, or writing files. All functions are preceded by the <code>file:</code> prefix. Some changes might happen to this module, as it is currently aligned with the upcoming [http://expath.org/spec/file EXPath] specification.
+
This [[Module Library|XQuery Module]] contains functions related to file system operations, such as listing, reading, or writing files.
  
−
==file:exists==
+
This module is based on the [http://expath.org/spec/file EXPath File Module]. The following enhancements have not been added to the specification yet:
−
{|
+
 
−
|-
+
{| class="wikitable"
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:exists</b>($path as xs:string) as xs:boolean</code><br />
+
! Function
−
|-
+
! Description
−
| valign='top' | '''Summary'''
+
|- valign="top"
−
|Checks if a path exist.
+
| {{Function||file:descendants}}
−
|-
+
| new function
−
| valign='top' | '''Rules'''
+
|- valign="top"
−
|This function returns an <code>xs:boolean</code> indicating whether a file or directory specified by <code>$path</code> exists in the file system.<br />
+
| {{Function||file:is-absolute}}
 +
| new function
 +
|- valign="top"
 +
| {{Function||file:read-text}}, {{Function||file:read-text-lines}}
 +
| <code>$fallback</code> argument added
 +
|- valign="top"
 +
| {{Function||file:read-text-lines}}
 +
| <code>$offset</code> and <code>$length</code> arguments added
 +
|- valign="top"
 +
| {{Function||file:resolve-path}}
 +
| <code>$base</code> argument added
 +
|}
 +
 
 +
=Conventions=
 +
 
 +
All functions and errors in this module are assigned to the <code><nowiki>http://expath.org/ns/file</nowiki></code> namespace, which is statically bound to the {{Code|file}} prefix.<br/>
 +
 
 +
For serialization parameters, the <code><nowiki>http://www.w3.org/2010/xslt-xquery-serialization</nowiki></code> namespace is used, which is statically bound to the {{Code|output}} prefix.<br/>
 +
 
 +
The error <code>[[#Errors|invalid-path]]</code> is raised if a path is invalid.
 +
 
 +
==File Paths==
 +
 
 +
* All file paths are resolved against the ''current working directory'' (the directory from which BaseX or, more generally, the Java Virtual Machine, was started). This directory can be retrieved via {{Function||file:base-dir}}.
 +
 
 +
* A path can be specified as local filesystem path or as file URI.
 +
 
 +
* Returned strings that refer to existing directories are suffixed with a directory separator.
 +
 
 +
=Read Operations=
 +
 
 +
==file:list==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:list(
 +
  $dir        as xs:string,
 +
  $recursive  as xs:boolean?  := false(),
 +
  $pattern    as xs:string    := ()
 +
) as xs:string*</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Lists all files and directories found in the specified {{Code|$dir}}. The returned paths are relative to the provided path.<br/>If {{Code|$recursive}} is set to true, subdirectories will be traversed.<br/>The optional parameter {{Code|$pattern}} defines a file name pattern in the [[Commands#Glob_Syntax|Glob Syntax]]. If present, only those files and directories are returned that correspond to the pattern. Several patterns can be separated with a comma ({{Code|,}}).<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|no-dir|#Errors}} the specified path does not point to a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
| Return the contents of large {{Code|.txt}} files located in a specific directory and its subdirectories:
 +
<pre lang='xquery'>
 +
let $root := 'path/to/files/'
 +
for $file in file:list($root, true(), '*.txt')
 +
let $path := $root || $file
 +
where file:size($path) > 1000000
 +
return file:read-text($path)
 +
</pre>
 
|}
 
|}
  
−
==file:is-directory==
+
==file:children==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:is-directory</b>($path as xs:string) as xs:boolean</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:children(
−
| valign='top' | '''Summary'''
+
  $dir  as xs:string
−
|Checks if a path points to a directory.
+
) as xs:string*</pre>
−
|-
+
|- valign="top"
−
| valign='top' | '''Rules'''
+
| '''Summary'''
−
|This function returns an <code>xs:boolean</code> indicating whether the argument <code>$path</code> points to an existing directory.<br />
+
|Returns the full paths to all files and directories found in the specified {{Code|$dir}}.<br/>The inverse function is {{Function||file:parent}}. The returned paths start with the specified directory. The related function {{Function||file:list}} returns relative file paths.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|no-dir|#Errors}} the specified path does not point to a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
| Return the contents of large {{Code|.txt}} files located in a specific directory:
 +
<pre lang='xquery'>
 +
for $file in file:children('path/to/files/')
 +
where matches($file, '.txt', 'i') and file:size($file) > 1000000
 +
return file:read-text($$file)
 +
</pre>
 
|}
 
|}
  
−
==file:is-file==
+
==file:descendants==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:is-file</b>($path as xs:string) as xs:boolean</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:descendants(
−
| valign='top' | '''Summary'''
+
  $dir  as xs:string
−
|Checks if a path points to a file.
+
) as xs:string*</pre>
−
|-
+
|- valign="top"
−
| valign='top' | '''Rules'''
+
| '''Summary'''
−
|This function returns an <code>xs:boolean</code> indicating whether the argument <code>$path</code> points to an existing file.<br />
+
|Returns the full paths to all files and directories found in the specified {{Code|$dir}} and its subdirectories.<br/>. The returned paths start with the specified directory. The related function {{Function||file:list}} creates relative file paths.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|no-dir|#Errors}} the specified path does not point to a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
| Return the contents of all {{Code|.txt}} files located in a specific directory and its subdirectories:
 +
<pre lang='xquery'>
 +
for $file in file:descendants('path/to/files/')
 +
where matches($file, '.txt', 'i') and file:size($file) > 1000000
 +
return file:read-text($$file)
 +
</pre>
 
|}
 
|}
  
−
==file:is-readable==
+
==file:read-binary==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:is-readable</b>($path as xs:string) as xs:boolean</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:read-binary(
−
| valign='top' | '''Summary'''
+
  $path   as xs:string,
−
|Checks if a file is readable.
+
  $offset  as xs:integer  := (),
−
|-
+
  $length  as xs:integer  := ()
−
| valign='top' | '''Rules'''
+
) as xs:base64Binary</pre>
−
|This function returns an <code>xs:boolean</code> indicating whether the file specified by <code>$path</code> exists and is readable.<br />
+
|- valign="top"
 +
| '''Summary'''
 +
|Reads the binary content of the file specified by {{Code|$path}} and returns it as [[Lazy Module|lazy]] {{Code|xs:base64Binary}} item.<br/>The optional parameters {{Code|$offset}} and {{Code|$length}} can be used to read chunks of a file.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|out-of-range|#Errors}} the offset or length is negative, or the chosen values would exceed the file bounds.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
|
 +
* <code><nowiki>lazy:cache(file:read-binary("config.data"))</nowiki></code> enforces the file access (otherwise, it will be delayed until requested first).
 
|}
 
|}
  
−
==file:is-writable==
+
==file:read-text==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:is-writable</b>($path as xs:string) as xs:boolean</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:read-text(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Checks if a file is writable.
+
  $encoding  as xs:string   := (),
−
|-
+
  $fallback  as xs:boolean?  := false()
−
| valign='top' | '''Rules'''
+
) as xs:string</pre>
−
|This function returns an <code>xs:boolean</code> indicating whether the file specified by <code>$path</code> exists and is writable.<br />
+
|- valign="top"
 +
| '''Summary'''
 +
|Reads the textual contents of the file specified by {{Code|$path}} and returns it as [[Lazy Module|lazy]] {{Code|xs:string}} item:
 +
* The UTF-8 default encoding can be overwritten with the optional {{Code|$encoding}} argument.
 +
* By default, invalid XML characters will be rejected. If {{Code|$fallback}} is enabled, the characters will be replaced with the Unicode replacement character <code>FFFD</code> (&#xFFFD;).
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.
 +
|- valign="top"
 +
| '''Examples'''
 +
|
 +
* <code><nowiki>lazy:cache(file:read-text("ids.txt"))</nowiki></code> enforces the file access (otherwise, it will be delayed until requested first).
 
|}
 
|}
  
−
==file:last-modified==
+
==file:read-text-lines==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:last-modified</b>($path as xs:string) as xs:dateTime</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:read-text-lines(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Returns the timestamp of a path.
+
  $encoding  as xs:string   := (),
−
|-
+
  $fallback  as xs:boolean?  := false(),
−
| valign='top' | '''Rules'''
+
  $offset    as xs:integer?  := (),
−
|This function retrieves the timestamp of the last modification of the file or directory specified by <code>$path</code>.<br />
+
  $length    as xs:integer?  := ()
−
|-
+
) as xs:string*</pre>
−
| valign='top' | '''Errors'''
+
|- valign="top"
−
|<b>[FOFL0001]</b> is raised if the specified path does not exist.<br />
+
| '''Summary'''
 +
|Reads the textual contents of the file specified by {{Code|$path}} and returns it as a sequence of {{Code|xs:string}} items:
 +
* The UTF-8 default encoding can be overwritten with the optional {{Code|$encoding}} argument.
 +
* By default, invalid characters will be rejected. If {{Code|$fallback}} is set to true, these characters will be replaced with the Unicode replacement character <code>FFFD</code> (&#xFFFD;).
 +
The lines to be read can be restricted with the optional parameters {{Code|$offset}} and {{Code|$length}}.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:size==
+
=Write Operations=
−
{|
+
 
−
|-
+
==file:create-dir==
−
| valign='top' width='90' | '''Signatures'''
+
 
−
|<code><b>file:size</b>($path as xs:string) as xs:integer</code><br />
+
{| width='100%'
−
|-
+
|- valign="top"
−
| valign='top' | '''Summary'''
+
| width='120' | '''Signature'''
−
|Returns the size of a file.
+
|<pre>file:create-dir(
−
|-
+
  $dir  as xs:string
−
| valign='top' | '''Rules'''
+
) as empty-sequence()</pre>
−
|This function returns the size, in bytes, of the file specified by <code>$path</code>. The return value is unspecified if the argument points to a directory.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Creates the directory specified by {{Code|$dir}} if it does not already exist. Non-existing parent directories will be created as well.<br/>
−
|<b>[FOFL0001]</b> is raised if the specified path does not exist.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|exists|#Errors}} the specified target exists, but is no directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:list==
+
==file:create-temp-dir==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:list</b>($path as xs:string) as xs:string*</code><br /><code><b>file:list</b>($path as xs:string, $recursive as xs:boolean) as xs:string*</code><br /><code><b>file:list</b>($path as xs:string, $recursive as xs:boolean, $pattern as xs:string) as xs:string*</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:create-temp-dir(
−
| valign='top' | '''Summary'''
+
  $prefix  as xs:string,
−
|Lists the contents of a directory.
+
  $suffix  as xs:string,
−
|-
+
  $dir    as xs:string := ()
−
| valign='top' | '''Rules'''
+
) as xs:string</pre>
−
|This function lists all files and directories found in the directory that is specified by <code>$path</code>. The returned paths are relative to the provided path.<br />The optional parameter <code>$recursive</code> specifies whether the sub-directories are to be recursed as well.<br />The optional parameter <code>$pattern</code> defines a file name pattern. If present, only those files and directories are returned that correspond to the pattern. A pattern may contain asterisks (<code>*</code>) to match zero or more characters, and question marks (<code>?</code>) to match single characters. Several patterns can be separated with a comma (<code>,</code>).<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Creates a new temporary directory that did not exist before this function was called, and returns its full file path. The directory name begins and ends with the specified {{Code|$prefix}} and {{Code|$suffix}}. If no directory is specified via {{Code|$dir}}, the directory will be placed in the system’s default temporary directory. The operation will create all non-existing parent directories.
−
|<b>[FOFL0001]</b> is raised if the specified path does not exist.<br /><b>[FOFL0003]</b> is raised if the specified path does not point to a directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the specified directory points to a file.<br/>{{Error|io-error|#Errors}} the directory could not be created.
 
|}
 
|}
  
−
==file:create-directory==
+
==file:create-temp-file==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:create-directory</b>($path as xs:string) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:create-temp-file(
−
| valign='top' | '''Summary'''
+
  $prefix  as xs:string,
−
|Creates a new directory path.
+
  $suffix  as xs:string,
−
|-
+
  $dir    as xs:string  := ()
−
| valign='top' | '''Rules'''
+
) as xs:string</pre>
−
|This function recursively creates the directories specified by <code>$path</code>.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Creates a new temporary file that did not exist before this function was called, and returns its full file path. The file name begins and ends with the specified {{Code|$prefix}} and {{Code|$suffix}}. If no directory is specified via {{Code|$dir}}, the file will be placed in the system’s default temporary directory. The operation will create all non-existing parent directories.
−
|<b>[FOFL0002]</b> is raised if a file with the same path already exists.<br /><b>[FOFL0006]</b> is raised if the specified path is invalid (e.g., contains invalid characters).<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the specified directory points to a file.<br/>{{Error|io-error|#Errors}} the directory could not be created.
 
|}
 
|}
  
 
==file:delete==
 
==file:delete==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:delete</b>($path as xs:string) as empty-sequence()</code><br /><code><b>file:delete</b>($path as xs:string, $recursive as xs:boolean) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:delete(
−
| valign='top' | '''Summary'''
+
  $path       as xs:string,
−
|Deletes a file or directory.
+
  $recursive as xs:boolean?  := false()
−
|-
+
) as empty-sequence()</pre>
−
| valign='top' | '''Rules'''
+
|- valign="top"
−
|This function deletes a file or directory specified by <code>$path</code>. No operation will be performed if the specified path does not exist.<br />If the optional parameter <code>$recursive</code> is provided, the operation is performed recursively for all sub-directories of the given path.<br />
+
| '''Summary'''
−
|-
+
|Recursively deletes a file or directory specified by {{Code|$path}}.<br/>The optional parameter {{Code|$recursive}} specifies whether subdirectories will be deleted, too.<br/>
−
| valign='top' | '''Errors'''
+
|- valign="top"
−
|<b>[FOFL0005]</b> is raised if <code>$recursive</code> is not specified or set to <code>false</code>, and if the specified path points to a non-empty directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified path does not exist.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:read==
+
==file:write==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:read</b>($path as xs:string) as xs:string</code><br /><code><b>file:read</b>($path as xs:string, $encoding as xs:string) as xs:string</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:write(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Reads the contents a file.
+
  $input    as item()*,
−
|-
+
  $options  as map(*)?    := map { }
−
| valign='top' | '''Rules'''
+
) as empty-sequence()</pre>
−
|This function reads the textual contents of the file specified by <code>$path</code> and returns it as a <code>xs:string</code>.<br />The optional parameter <code>$encoding</code> defines the encoding of the file.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Writes serialized {{Code|$input}} to the specified file. If the file already exists, it will be overwritten.<br/>The {{Code|$options}} argument contains [[Serialization|serialization parameters]]. As with [https://www.w3.org/TR/xpath-functions-31/#func-serialize fn:serialize()], the parameters can be specified<br/>
−
|<b>[FOFL0001]</b> is raised if the specified file does not exist.<br /><b>[FOFL0004]</b> is raised if the specified path is a directory.<br /><b>[FOFL0007]</b> is raised if the specified encoding is not supported, or unknown.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
* either as children of an {{Code|&lt;output:serialization-parameters/&gt;}} element:
 +
<pre lang="xml">
 +
<output:serialization-parameters>
 +
  <output:method value='xml'/>
 +
  <output:cdata-section-elements value="div"/>
 +
  ...
 +
</output:serialization-parameters>
 +
</pre>
 +
* or as map, which contains all key/value pairs:
 +
<pre lang='xquery'>
 +
map { "method": "xml", "cdata-section-elements": "div", ... }
 +
</pre>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
|
 +
* <code><nowiki>file:write('data.bin', xs:hexBinary('414243'))</nowiki></code> writes a hex representation to the specified file.
 +
* <code><nowiki>file:write('data.bin', xs:hexBinary('414243'), map { 'method': 'basex')</nowiki></code> writes binary data to the specified file (see [[XQuery_Extensions#Serialization|Serialization]] for more details).
 +
|}
 +
 
 +
==file:write-binary==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:write-binary(
 +
  $path    as xs:string,
 +
  $value  as xs:anyAtomicType,
 +
  $offset  as xs:integer        := ()
 +
) as empty-sequence()</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Writes a binary item (xs:base64Binary, xs:hexBinary) to the specified file. If the file already exists, it will be overwritten.<br/>If {{Code|$offset}} is specified, data will be written at this file position. An existing file may be resized by that operation.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|out-of-range|#Errors}} the offset is negative, or it exceeds the current file size.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|}
 +
 
 +
==file:write-text==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:write-text(
 +
  $path      as xs:string,
 +
  $value    as xs:string,
 +
  $encoding  as xs:string  := ()
 +
) as empty-sequence()</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Writes a string to the specified file. If the file already exists, it will be overwritten.<br/>The optional parameter {{Code|$encoding}} defines the output encoding (default: UTF-8).<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:read-binary==
+
==file:write-text-lines==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:read-binary</b>($path as xs:string) as xs:base64Binary</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:write-text-lines(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Reads the binary contents of a file.
+
  $values    as xs:string*,
−
|-
+
  $encoding  as xs:string  := ()
−
| valign='top' | '''Rules'''
+
) as empty-sequence()</pre>
−
|This function reads the binary content of the file specified by <code>$path</code> and returns as a <code>xs:base64Binary</code>.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Writes a sequence of strings to the specified file, each followed by the system specific newline character. If the file already exists, it will be overwritten.<br/>The optional parameter {{Code|$encoding}} defines the output encoding (default: UTF-8).<br/>
−
|<b>[FOFL0001]</b> is raised if the specified file does not exist.<br /><b>[FOFL0004]</b> is raised if the specified path is a directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|}
 +
 
 +
==file:append==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:append(
 +
  $path     as xs:string,
 +
  $input    as item()*,
 +
  $options  as map(*)?    := map { }
 +
) as empty-sequence()</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Appends a serialized sequence of {{Code|$input}} to the specified file, with the supplied {{Code|$options}} as serialization parameters. If the file does not exist, a new file is created.<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|}
 +
 
 +
==file:append-binary==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:append-binary(
 +
  $path  as xs:string,
 +
  $value  as xs:anyAtomicType
 +
) as empty-sequence()</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Appends a binary item (xs:base64Binary, xs:hexBinary) to the specified file. If the file does not exists, a new one is created.<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:write==
+
==file:append-text==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:write</b>($path as xs:string, $items as xs:item()*) as empty-sequence()</code><br /><code><b>file:write</b>($path as xs:string, $items as xs:item()*, $params as xs:node()*) as empty-sequence()</code><br /><code><b>file:write</b>($path as xs:string, $items as xs:item()*, $params as xs:node()*, $append as xs:boolean) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:append-text(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Writes a sequence of items to a file.
+
  $value    as xs:string,
−
|-
+
  $encoding  as xs:string := ()
−
| valign='top' | '''Rules'''
+
) as empty-sequence()</pre>
−
|This function writes a sequence, specified by <code>$items</code>, to a file specified by <code>$path</code>. If the specified file already exists, it will be overwritten.<br />The optional argument <code>$params</code> is used to set the serialization parameters, as defined in [http://www.w3.org/TR/xslt-xquery-serialization/ XSLT 2.0 and XQuery 1.0 Serialization].<br />If the <code>$append</code> flag is set to <code>true</code>, the serialized items are appended to the original file. If the file does not exist, a new one is created.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Appends a string to a file specified by {{Code|$path}}. If the specified file does not exists, a new file is created.<br/>The optional parameter {{Code|$encoding}} defines the output encoding (default: UTF-8).<br/>
−
|<b>[FOFL0004]</b> is raised if the specified path is a directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
−
==file:write-binary==
+
==file:append-text-lines==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:write-binary</b>($path as xs:string, $item as xs:base64Binary) as empty-sequence()</code><br /><code><b>file:write-binary</b>($path as xs:string, $item as xs:base64Binary, $append as xs:boolean) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:append-text-lines(
−
| valign='top' | '''Summary'''
+
  $path     as xs:string,
−
|Writes a sequence of items to a file.
+
  $values    as xs:string*,
−
|-
+
  $encoding  as xs:string  := ()
−
| valign='top' | '''Rules'''
+
) as empty-sequence()</pre>
−
|This function writes a <code>xs:basex64Binary</code> item specified by <code>$item</code> to a file specified by <code>$path</code>. If the specified file already exists, it will be overwritten.<br />If the <code>$append</code> flag is set to <code>true</code>, the serialized item is appended to the original file. If the file does not exist, a new one is created.<br />
+
|- valign="top"
−
|-
+
| '''Summary'''
−
| valign='top' | '''Errors'''
+
|Appends a sequence of strings to the specified file, each followed by the system specific newline character. If the specified file does not exists, a new file is created.<br/>The optional parameter {{Code|$encoding}} defines the output encoding (default: UTF-8).<br/>
−
|<b>[FOFL0004]</b> is raised if the specified path is a directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|no-dir|#Errors}} the parent of specified path is no directory.<br/>{{Error|is-dir|#Errors}} the specified path is a directory.<br/>{{Error|unknown-encoding|#Errors}} the specified encoding is not supported, or unknown.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
 
==file:copy==
 
==file:copy==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:copy</b>($source as xs:string, $target as xs:string) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:copy(
−
| valign='top' | '''Summary'''
+
  $source as xs:string,
−
|Copies a file.
+
  $target as xs:string
−
|-
+
) as empty-sequence()</pre>
−
| valign='top' | '''Rules'''
+
|- valign="top"
−
|This function copies a file specified by <code>$source</code> to the file or directory specified by <code>$target</code>. If the target represents an existing file, it will be overwritten. No operation will be performed if the source and target path are equal.<br />
+
| '''Summary'''
−
|-
+
|Copies a file or directory specified by {{Code|$source}} to the file or directory specified by {{Code|$target}}. If the target file already exists, it will be overwritten. No operation will be performed if the source and target path are equal.<br/>
−
| valign='top' | '''Errors'''
+
|- valign="top"
−
|<b>[FOFL0001]</b> is raised if the specified source does not exist.<br /><b>[FOFL0004]</b> is raised if the specified source is a directory.<br /><b>[FOFL0006]</b> is raised if the specified target path points to a file in a non-existing directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified source does not exist.<br/>{{Error|exists|#Errors}} the specified source is a directory and the target is a file.<br/>{{Error|no-dir|#Errors}} the parent of the specified target is no directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 
|}
 
|}
  
 
==file:move==
 
==file:move==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:move</b>($source as xs:string, $target as xs:string) as empty-sequence()</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:move(
−
| valign='top' | '''Summary'''
+
  $source as xs:string,
−
|Moves a file.
+
  $target as xs:string
−
|-
+
) as empty-sequence()</pre>
−
| valign='top' | '''Rules'''
+
|- valign="top"
−
|This function moves, or renames, the file or directory specified by <code>$source</code> to the path specified by <code>$target</code>. No operation will be performed if the source and target path are equal.<br />
+
| '''Summary'''
−
|-
+
|Moves or renames the file or directory specified by {{Code|$source}} to the path specified by {{Code|$target}}. If the target file already exists, it will be overwritten. No operation will be performed if the source and target path are equal.<br/>
−
| valign='top' | '''Errors'''
+
|- valign="top"
−
|<b>[FOFL0001]</b> is raised if the specified source does not exist.<br /><b>[FOFL0006]</b> is raised if the specified target path points to a file in a non-existing directory.<br /><b>[FOFL0008]</b> is raised if the operation fails for some other reason.<br />
+
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified source does not exist.<br/>{{Error|exists|#Errors}} the specified source is a directory and the target is a file.<br/>{{Error|no-dir|#Errors}} the parent of the specified target is no directory.<br/>{{Error|io-error|#Errors}} the operation fails for some other reason.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
|When renaming a file, remember that relative file paths are resolved against the current working directory. Some ways to rename:
 +
<pre lang='xquery'>
 +
file:move('/projects/new/octopus', '/projects/new/septimus')
 +
</pre>
 +
<pre lang='xquery'>
 +
$path ! file:move(., file:parent(.)||$newName)
 +
</pre>
 +
 
 +
|}
 +
 
 +
=File Properties=
 +
 
 +
==file:exists==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:exists(
 +
  $path  as xs:string
 +
) as xs:boolean</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns an {{Code|xs:boolean}} indicating whether a file or directory specified by {{Code|$path}} exists in the file system.<br/>
 +
|}
 +
 
 +
==file:is-dir==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:is-dir(
 +
  $path  as xs:string
 +
) as xs:boolean</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns an {{Code|xs:boolean}} indicating whether the argument {{Code|$path}} points to an existing directory.<br/>
 +
|}
 +
 
 +
==file:is-absolute==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:is-absolute(
 +
  $path  as xs:string
 +
) as xs:boolean</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns an {{Code|xs:boolean}} indicating whether the argument {{Code|$path}} is absolute.<br/>The behavior of this function depends on the operating system: On Windows, an absolute path starts with the drive letter and a colon, whereas on Linux it starts with a slash.
 +
|}
 +
 
 +
==file:is-file==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:is-file(
 +
  $path  as xs:string
 +
) as xs:boolean</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns an {{Code|xs:boolean}} indicating whether the argument {{Code|$path}} points to an existing file.<br/>
 +
|}
 +
 
 +
==file:last-modified==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:last-modified(
 +
  $path  as xs:string
 +
) as xs:dateTime</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Retrieves the timestamp of the last modification of the file or directory specified by {{Code|$path}}.<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified path does not exist.<br/>
 +
|}
 +
 
 +
==file:size==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:size(
 +
  $path  as xs:string
 +
) as xs:integer</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the size, in bytes, of the file specified by {{Code|$path}}, or {{Code|0}} for directories.<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>
 +
|}
 +
 
 +
=Path Functions=
 +
 
 +
==file:name==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:name(
 +
  $path as xs:string
 +
) as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the name of a file or directory specified by {{Code|$path}}. An empty string is returned if the path points to the root directory.
 +
|}
 +
 
 +
==file:parent==
 +
 
 +
{| width='100%'
 +
 
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:parent(
 +
  $path  as xs:string
 +
) as xs:string?</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the absolute path to the parent directory of a file or directory specified by {{Code|$path}}. An empty sequence is returned if the path points to a root directory.<br/>The inverse function is {{Function||file:children}}.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
|
 +
* <code><nowiki>file:parent(static-base-uri())</nowiki></code> returns the directory of the current XQuery module.
 +
|}
 +
 
 +
==file:path-to-native==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:path-to-native(
 +
  $path  as xs:string
 +
) as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Transforms the {{Code|$path}} argument to its native representation on the operating system.<br/>
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|not-found|#Errors}} the specified file does not exist.<br/>{{Error|io-error|#Errors}} the specified path cannot be transformed to its native representation.<br/>
 +
|}
 +
 
 +
==file:resolve-path==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:resolve-path(
 +
  $path  as xs:string,
 +
  $base  as xs:string  := ()
 +
) as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Transforms the {{Code|$path}} argument to an absolute operating system path.<br/>If the path is relative, and if an absolute {{Code|$base}} path is specified, it will be resolved against this path.
 +
|- valign="top"
 +
| '''Errors'''
 +
|{{Error|is-relative|#Errors}} the specified base path is relative.<br/>
 +
|- valign="top"
 +
| '''Examples'''
 +
|The following examples apply to Windows:
 +
* {{Code|file:resolve-path('file.txt', 'C:/Temp/')}} returns {{Code|C:/Temp/file.txt}}.
 +
* {{Code|file:resolve-path('file.txt', 'C:/Temp')}} returns {{Code|C:/file.txt}}.
 +
* {{Code|file:resolve-path('file.txt', 'Temp')}} raises an error.
 +
|}
 +
 
 +
==file:path-to-uri==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:path-to-uri(
 +
  $path  as xs:string
 +
) as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Transforms the path specified by {{Code|$path}} into a URI with the {{Code|file://}} scheme.<br/>
 +
|}
 +
 
 +
=System Properties=
 +
 
 +
==file:dir-separator==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|{{Code|'''file:dir-separator'''() as xs:string}}<br/>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the directory separator used by the operating system, such as {{Code|/}} or {{Code|\}}.<br/>
 
|}
 
|}
  
 
==file:path-separator==
 
==file:path-separator==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:path-separator</b>() as xs:string</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|{{Code|'''file:path-separator'''() as xs:string}}<br/>
−
| valign='top' | '''Summary'''
+
|- valign="top"
−
|Returns the path separator.
+
| '''Summary'''
−
|-
+
|Returns the path separator used by the operating system, such as {{Code|;}} or {{Code|:}}.<br/>
−
| valign='top' | '''Rules'''
+
|}
−
|This function returns the path separator used by the operating system.<br />
+
 
 +
==file:line-separator==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:line-separator() as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the line separator used by the operating system, such as {{Code|&amp;#10;}}, {{Code|&amp;#13;&amp;#10;}} or {{Code|&amp;#13;}}.<br/>
 +
|}
 +
 
 +
==file:temp-dir==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:temp-dir() as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the system’s default temporary-file directory.<br/>
 +
|}
 +
 
 +
==file:current-dir==
 +
 
 +
{| width='100%'
 +
|- valign="top"
 +
| width='120' | '''Signature'''
 +
|<pre>file:current-dir() as xs:string</pre>
 +
|- valign="top"
 +
| '''Summary'''
 +
|Returns the ''current working directory'', i.e., the directory from which the query processor was started. This function returns the same result as the function call <code>file:resolve-path("")</code>.
 
|}
 
|}
  
−
==file:path-to-full-path==
+
==file:base-dir==
−
{|
+
 
−
|-
+
{| width='100%'
−
| valign='top' width='90' | '''Signatures'''
+
|- valign="top"
−
|<code><b>file:path-to-full-path</b>($path as xs:string) as xs:string</code><br />
+
| width='120' | '''Signature'''
−
|-
+
|<pre>file:base-dir() as xs:string?</pre>
−
| valign='top' | '''Summary'''
+
|- valign="top"
−
|Returns a full path representation.
+
| '''Summary'''
−
|-
+
|Returns the parent directory of the static base URI.<br/>If the static base URI is undefined or does not point to a local resource, it returns the empty sequence. Otherwise, it returns the same result as {{Code|file:parent(static-base-uri())}}.
−
| valign='top' | '''Rules'''
 
−
|This function transforms the path specified by <code>$path</code> into a full operating system path.<br />
 
 
|}
 
|}
  
−
==file:path-to-uri==
+
=Errors=
−
{|
+
 
−
|-
+
{| class="wikitable" width="100%"
−
| valign='top' width='90' | '''Signatures'''
+
! width="160"|Code
−
|<code><b>file:path-to-uri</b>($path as xs:string) as xs:string</code><br />
+
|Description
−
|-
+
|- valign="top"
−
| valign='top' | '''Summary'''
+
|{{Code|exists}}
−
|Returns a URI representation.
+
|A file with the same path already exists.
−
|-
+
|- valign="top"
−
| valign='top' | '''Rules'''
+
|{{Code|invalid-path}}
−
|This function transforms the path specified by <code>$path</code> into a URI with the <code>file://</code> scheme.<br />
+
|A specified path is invalid.
 +
|- valign="top"
 +
|{{Code|io-error}}
 +
|The operation fails for some other reason specific to the operating system.
 +
|- valign="top"
 +
|{{Code|is-dir}}
 +
|The specified path is a directory.
 +
|- valign="top"
 +
|{{Code|is-relative}}
 +
|The specified path is relative (and must be absolute).
 +
|- valign="top"
 +
|{{Code|no-dir}}
 +
|The specified path does not point to a directory.
 +
|- valign="top"
 +
|{{Code|not-found}}
 +
|A specified path does not exist.
 +
|- valign="top"
 +
|{{Code|out-of-range}}
 +
|The specified offset or length is negative, or the chosen values would exceed the file bounds.
 +
|- valign="top"
 +
|{{Code|unknown-encoding}}
 +
|The specified encoding is not supported, or unknown.
 
|}
 
|}
  
−
[[Category:XQuery]]
+
=Changelog=
 +
 
 +
;Version 9.3
 +
* Added: {{Function||file:descendants}}
 +
 
 +
;Version 9.0
 +
* Updated: {{Function||file:read-text-lines}}: <code>$offset</code> and <code>$length</code> arguments added.
 +
 
 +
;Version 8.5
 +
* Updated: {{Function||file:read-text}}, {{Function||file:read-text-lines}}: <code>$fallback</code> argument added.
 +
 
 +
;Version 8.2
 +
* Added: {{Function||file:is-absolute}}
 +
* Updated: {{Function||file:resolve-path}}: base argument added
 +
 
 +
;Version 8.0
 +
* Added: {{Function||file:current-dir}}, {{Function||file:base-dir}}, {{Function||file:children}}
 +
 
 +
;Version 7.8
 +
* Added: {{Function||file:parent}}, {{Function||file:name}}
 +
* Updated: error codes; {{Function||file:read-binary}}, {{Function||file:write-binary}}: {{Code|$offset}} and {{Code|$length}} arguments added.
 +
* Deleted: file:base-name, file:dir-name
 +
 
 +
;Version 7.7
 +
* Added: {{Function||file:create-temp-dir}}, {{Function||file:create-temp-file}}, {{Function||file:temp-dir}}
 +
* Updated: all returned strings that refer to existing directories will be suffixed with a directory separator.
 +
 
 +
;Version 7.3
 +
* Added: {{Function||file:append-text}}, {{Function||file:write-text}}, {{Function||file:append-text-lines}}, {{Function||file:write-text-lines}}, {{Function||file:line-separator}}
 +
* Aligned with latest specification: $file:directory-separator → {{Function||file:dir-separator}}, $file:path-separator → {{Function||file:path-separator}}, file:is-directory → {{Function||file:is-dir}}, file:create-directory → {{Function||file:create-dir}}
 +
* Updated: {{Function||file:write-binary}}, {{Function||file:append-binary}}: output limited to a single value
 +
 
 +
;Version 7.2.1
 +
* Updated: {{Function||file:delete}}: {{Code|$recursive}} parameter added to prevent subdirectories from being accidentally deleted.
 +
* Fixed: {{Function||file:list}} now returns relative instead of absolute paths.

Latest revision as of 19:20, 26 March 2024

This XQuery Module contains functions related to file system operations, such as listing, reading, or writing files.

This module is based on the EXPath File Module. The following enhancements have not been added to the specification yet:

Function Description
file:descendants new function
file:is-absolute new function
file:read-text, file:read-text-lines $fallback argument added
file:read-text-lines $offset and $length arguments added
file:resolve-path $base argument added

Conventions[edit]

All functions and errors in this module are assigned to the http://expath.org/ns/file namespace, which is statically bound to the file prefix.

For serialization parameters, the http://www.w3.org/2010/xslt-xquery-serialization namespace is used, which is statically bound to the output prefix.

The error invalid-path is raised if a path is invalid.

File Paths[edit]

  • All file paths are resolved against the current working directory (the directory from which BaseX or, more generally, the Java Virtual Machine, was started). This directory can be retrieved via file:base-dir.
  • A path can be specified as local filesystem path or as file URI.
  • Returned strings that refer to existing directories are suffixed with a directory separator.

Read Operations[edit]

file:list[edit]

Signature 
file:list(
  $dir        as xs:string,
  $recursive  as xs:boolean?  := false(),
  $pattern    as xs:string    := ()
) as xs:string*
Summary Lists all files and directories found in the specified $dir. The returned paths are relative to the provided path.
If $recursive is set to true, subdirectories will be traversed.
The optional parameter $pattern defines a file name pattern in the Glob Syntax. If present, only those files and directories are returned that correspond to the pattern. Several patterns can be separated with a comma (,).
Errors not-found: the specified file does not exist.
no-dir: the specified path does not point to a directory.
io-error: the operation fails for some other reason.
Examples Return the contents of large .txt files located in a specific directory and its subdirectories: 
let $root := 'path/to/files/'
for $file in file:list($root, true(), '*.txt')
let $path := $root || $file
where file:size($path) > 1000000
return file:read-text($path)

file:children[edit]

Signature 
file:children(
  $dir  as xs:string
) as xs:string*
Summary Returns the full paths to all files and directories found in the specified $dir.
The inverse function is file:parent. The returned paths start with the specified directory. The related function file:list returns relative file paths.
Errors not-found: the specified file does not exist.
no-dir: the specified path does not point to a directory.
io-error: the operation fails for some other reason.
Examples Return the contents of large .txt files located in a specific directory: 
for $file in file:children('path/to/files/')
where matches($file, '.txt', 'i') and file:size($file) > 1000000
return file:read-text($$file)

file:descendants[edit]

Signature 
file:descendants(
  $dir  as xs:string
) as xs:string*
Summary Returns the full paths to all files and directories found in the specified $dir and its subdirectories.
. The returned paths start with the specified directory. The related function file:list creates relative file paths.
Errors not-found: the specified file does not exist.
no-dir: the specified path does not point to a directory.
io-error: the operation fails for some other reason.
Examples Return the contents of all .txt files located in a specific directory and its subdirectories: 
for $file in file:descendants('path/to/files/')
where matches($file, '.txt', 'i') and file:size($file) > 1000000
return file:read-text($$file)

file:read-binary[edit]

Signature 
file:read-binary(
  $path    as xs:string,
  $offset  as xs:integer  := (),
  $length  as xs:integer  := ()
) as xs:base64Binary
Summary Reads the binary content of the file specified by $path and returns it as lazy xs:base64Binary item.
The optional parameters $offset and $length can be used to read chunks of a file.
Errors not-found: the specified file does not exist.
is-dir: the specified path is a directory.
out-of-range: the offset or length is negative, or the chosen values would exceed the file bounds.
io-error: the operation fails for some other reason.
Examples
  • lazy:cache(file:read-binary("config.data")) enforces the file access (otherwise, it will be delayed until requested first).

file:read-text[edit]

Signature 
file:read-text(
  $path      as xs:string,
  $encoding  as xs:string   := (),
  $fallback  as xs:boolean?  := false()
) as xs:string
Summary Reads the textual contents of the file specified by $path and returns it as lazy xs:string item:
  • The UTF-8 default encoding can be overwritten with the optional $encoding argument.
  • By default, invalid XML characters will be rejected. If $fallback is enabled, the characters will be replaced with the Unicode replacement character FFFD (�).
Errors not-found: the specified file does not exist.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.
Examples
  • lazy:cache(file:read-text("ids.txt")) enforces the file access (otherwise, it will be delayed until requested first).

file:read-text-lines[edit]

Signature 
file:read-text-lines(
  $path      as xs:string,
  $encoding  as xs:string    := (),
  $fallback  as xs:boolean?  := false(),
  $offset    as xs:integer?  := (),
  $length    as xs:integer?  := ()
) as xs:string*
Summary Reads the textual contents of the file specified by $path and returns it as a sequence of xs:string items:
  • The UTF-8 default encoding can be overwritten with the optional $encoding argument.
  • By default, invalid characters will be rejected. If $fallback is set to true, these characters will be replaced with the Unicode replacement character FFFD (�).

The lines to be read can be restricted with the optional parameters $offset and $length.

Errors not-found: the specified file does not exist.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.

Write Operations[edit]

file:create-dir[edit]

Signature 
file:create-dir(
  $dir  as xs:string
) as empty-sequence()
Summary Creates the directory specified by $dir if it does not already exist. Non-existing parent directories will be created as well.
Errors exists: the specified target exists, but is no directory.
io-error: the operation fails for some other reason.

file:create-temp-dir[edit]

Signature 
file:create-temp-dir(
  $prefix  as xs:string,
  $suffix  as xs:string,
  $dir     as xs:string  := ()
) as xs:string
Summary Creates a new temporary directory that did not exist before this function was called, and returns its full file path. The directory name begins and ends with the specified $prefix and $suffix. If no directory is specified via $dir, the directory will be placed in the system’s default temporary directory. The operation will create all non-existing parent directories.
Errors no-dir: the specified directory points to a file.
io-error: the directory could not be created.

file:create-temp-file[edit]

Signature 
file:create-temp-file(
  $prefix  as xs:string,
  $suffix  as xs:string,
  $dir     as xs:string  := ()
) as xs:string
Summary Creates a new temporary file that did not exist before this function was called, and returns its full file path. The file name begins and ends with the specified $prefix and $suffix. If no directory is specified via $dir, the file will be placed in the system’s default temporary directory. The operation will create all non-existing parent directories.
Errors no-dir: the specified directory points to a file.
io-error: the directory could not be created.

file:delete[edit]

Signature 
file:delete(
  $path       as xs:string,
  $recursive  as xs:boolean?  := false()
) as empty-sequence()
Summary Recursively deletes a file or directory specified by $path.
The optional parameter $recursive specifies whether subdirectories will be deleted, too.
Errors not-found: the specified path does not exist.
io-error: the operation fails for some other reason.

file:write[edit]

Signature 
file:write(
  $path     as xs:string,
  $input    as item()*,
  $options  as map(*)?    := map { }
) as empty-sequence()
Summary Writes serialized $input to the specified file. If the file already exists, it will be overwritten.
The $options argument contains serialization parameters. As with fn:serialize(), the parameters can be specified
  • either as children of an <output:serialization-parameters/> element:
<output:serialization-parameters>
  <output:method value='xml'/>
  <output:cdata-section-elements value="div"/>
  ...
</output:serialization-parameters>
  • or as map, which contains all key/value pairs:
map { "method": "xml", "cdata-section-elements": "div", ... }
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
io-error: the operation fails for some other reason.
Examples
  • file:write('data.bin', xs:hexBinary('414243')) writes a hex representation to the specified file.
  • file:write('data.bin', xs:hexBinary('414243'), map { 'method': 'basex') writes binary data to the specified file (see Serialization for more details).

file:write-binary[edit]

Signature 
file:write-binary(
  $path    as xs:string,
  $value   as xs:anyAtomicType,
  $offset  as xs:integer        := ()
) as empty-sequence()
Summary Writes a binary item (xs:base64Binary, xs:hexBinary) to the specified file. If the file already exists, it will be overwritten.
If $offset is specified, data will be written at this file position. An existing file may be resized by that operation.
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
out-of-range: the offset is negative, or it exceeds the current file size.
io-error: the operation fails for some other reason.

file:write-text[edit]

Signature 
file:write-text(
  $path      as xs:string,
  $value     as xs:string,
  $encoding  as xs:string  := ()
) as empty-sequence()
Summary Writes a string to the specified file. If the file already exists, it will be overwritten.
The optional parameter $encoding defines the output encoding (default: UTF-8).
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.

file:write-text-lines[edit]

Signature 
file:write-text-lines(
  $path      as xs:string,
  $values    as xs:string*,
  $encoding  as xs:string   := ()
) as empty-sequence()
Summary Writes a sequence of strings to the specified file, each followed by the system specific newline character. If the file already exists, it will be overwritten.
The optional parameter $encoding defines the output encoding (default: UTF-8).
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.

file:append[edit]

Signature 
file:append(
  $path     as xs:string,
  $input    as item()*,
  $options  as map(*)?    := map { }
) as empty-sequence()
Summary Appends a serialized sequence of $input to the specified file, with the supplied $options as serialization parameters. If the file does not exist, a new file is created.
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
io-error: the operation fails for some other reason.

file:append-binary[edit]

Signature 
file:append-binary(
  $path   as xs:string,
  $value  as xs:anyAtomicType
) as empty-sequence()
Summary Appends a binary item (xs:base64Binary, xs:hexBinary) to the specified file. If the file does not exists, a new one is created.
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
io-error: the operation fails for some other reason.

file:append-text[edit]

Signature 
file:append-text(
  $path      as xs:string,
  $value     as xs:string,
  $encoding  as xs:string  := ()
) as empty-sequence()
Summary Appends a string to a file specified by $path. If the specified file does not exists, a new file is created.
The optional parameter $encoding defines the output encoding (default: UTF-8).
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.

file:append-text-lines[edit]

Signature 
file:append-text-lines(
  $path      as xs:string,
  $values    as xs:string*,
  $encoding  as xs:string   := ()
) as empty-sequence()
Summary Appends a sequence of strings to the specified file, each followed by the system specific newline character. If the specified file does not exists, a new file is created.
The optional parameter $encoding defines the output encoding (default: UTF-8).
Errors no-dir: the parent of specified path is no directory.
is-dir: the specified path is a directory.
unknown-encoding: the specified encoding is not supported, or unknown.
io-error: the operation fails for some other reason.

file:copy[edit]

Signature 
file:copy(
  $source  as xs:string,
  $target  as xs:string
) as empty-sequence()
Summary Copies a file or directory specified by $source to the file or directory specified by $target. If the target file already exists, it will be overwritten. No operation will be performed if the source and target path are equal.
Errors not-found: the specified source does not exist.
exists: the specified source is a directory and the target is a file.
no-dir: the parent of the specified target is no directory.
io-error: the operation fails for some other reason.

file:move[edit]

Signature 
file:move(
  $source  as xs:string,
  $target  as xs:string
) as empty-sequence()
Summary Moves or renames the file or directory specified by $source to the path specified by $target. If the target file already exists, it will be overwritten. No operation will be performed if the source and target path are equal.
Errors not-found: the specified source does not exist.
exists: the specified source is a directory and the target is a file.
no-dir: the parent of the specified target is no directory.
io-error: the operation fails for some other reason.
Examples When renaming a file, remember that relative file paths are resolved against the current working directory. Some ways to rename: 
file:move('/projects/new/octopus', '/projects/new/septimus')

$path ! file:move(., file:parent(.)||$newName)

File Properties[edit]

file:exists[edit]

Signature 
file:exists(
  $path  as xs:string
) as xs:boolean
Summary Returns an xs:boolean indicating whether a file or directory specified by $path exists in the file system.

file:is-dir[edit]

Signature 
file:is-dir(
  $path  as xs:string
) as xs:boolean
Summary Returns an xs:boolean indicating whether the argument $path points to an existing directory.

file:is-absolute[edit]

Signature 
file:is-absolute(
  $path  as xs:string
) as xs:boolean
Summary Returns an xs:boolean indicating whether the argument $path is absolute.
The behavior of this function depends on the operating system: On Windows, an absolute path starts with the drive letter and a colon, whereas on Linux it starts with a slash.

file:is-file[edit]

Signature 
file:is-file(
  $path  as xs:string
) as xs:boolean
Summary Returns an xs:boolean indicating whether the argument $path points to an existing file.

file:last-modified[edit]

Signature 
file:last-modified(
  $path  as xs:string
) as xs:dateTime
Summary Retrieves the timestamp of the last modification of the file or directory specified by $path.
Errors not-found: the specified path does not exist.

file:size[edit]

Signature 
file:size(
  $path  as xs:string
) as xs:integer
Summary Returns the size, in bytes, of the file specified by $path, or 0 for directories.
Errors not-found: the specified file does not exist.

Path Functions[edit]

file:name[edit]

Signature 
file:name(
  $path  as xs:string
) as xs:string
Summary Returns the name of a file or directory specified by $path. An empty string is returned if the path points to the root directory.

file:parent[edit]

Signature 
file:parent(
  $path  as xs:string
) as xs:string?
Summary Returns the absolute path to the parent directory of a file or directory specified by $path. An empty sequence is returned if the path points to a root directory.
The inverse function is file:children.
Examples
  • file:parent(static-base-uri()) returns the directory of the current XQuery module.

file:path-to-native[edit]

Signature 
file:path-to-native(
  $path  as xs:string
) as xs:string
Summary Transforms the $path argument to its native representation on the operating system.
Errors not-found: the specified file does not exist.
io-error: the specified path cannot be transformed to its native representation.

file:resolve-path[edit]

Signature 
file:resolve-path(
  $path  as xs:string,
  $base  as xs:string  := ()
) as xs:string
Summary Transforms the $path argument to an absolute operating system path.
If the path is relative, and if an absolute $base path is specified, it will be resolved against this path.
Errors is-relative: the specified base path is relative.
Examples The following examples apply to Windows:
  • file:resolve-path('file.txt', 'C:/Temp/') returns C:/Temp/file.txt.
  • file:resolve-path('file.txt', 'C:/Temp') returns C:/file.txt.
  • file:resolve-path('file.txt', 'Temp') raises an error.

file:path-to-uri[edit]

Signature 
file:path-to-uri(
  $path  as xs:string
) as xs:string
Summary Transforms the path specified by $path into a URI with the file:// scheme.

System Properties[edit]

file:dir-separator[edit]

Signature file:dir-separator() as xs:string
Summary Returns the directory separator used by the operating system, such as / or \.

file:path-separator[edit]

Signature file:path-separator() as xs:string
Summary Returns the path separator used by the operating system, such as ; or :.

file:line-separator[edit]

Signature 
file:line-separator() as xs:string
Summary Returns the line separator used by the operating system, such as &#10;, &#13;&#10; or &#13;.

file:temp-dir[edit]

Signature 
file:temp-dir() as xs:string
Summary Returns the system’s default temporary-file directory.

file:current-dir[edit]

Signature 
file:current-dir() as xs:string
Summary Returns the current working directory, i.e., the directory from which the query processor was started. This function returns the same result as the function call file:resolve-path("").

file:base-dir[edit]

Signature 
file:base-dir() as xs:string?
Summary Returns the parent directory of the static base URI.
If the static base URI is undefined or does not point to a local resource, it returns the empty sequence. Otherwise, it returns the same result as file:parent(static-base-uri()).

Errors[edit]

Code Description
exists A file with the same path already exists.
invalid-path A specified path is invalid.
io-error The operation fails for some other reason specific to the operating system.
is-dir The specified path is a directory.
is-relative The specified path is relative (and must be absolute).
no-dir The specified path does not point to a directory.
not-found A specified path does not exist.
out-of-range The specified offset or length is negative, or the chosen values would exceed the file bounds.
unknown-encoding The specified encoding is not supported, or unknown.

Changelog[edit]

Version 9.3
Version 9.0
Version 8.5
Version 8.2
Version 8.0
Version 7.8
Version 7.7
Version 7.3
Version 7.2.1
  • Updated: file:delete: $recursive parameter added to prevent subdirectories from being accidentally deleted.
  • Fixed: file:list now returns relative instead of absolute paths.
Retrieved from "http://docs.basex.org/index.php?title=File_Module&oldid=16926"