xref: /xsrc/external/mit/libXt/dist/specs/appA.xml

<appendix id='Resource_File_Format'>
<title>Resource File Format</title>
<para>
A resource file contains text representing the default resource values for an
application or set of applications.
</para>

<para>
The format of resource files is defined by
<emphasis remap='I'>Xlib — C Language X Interface.</emphasis> and is reproduced here
for convenience only.
</para>

<para>The format of a resource specification is</para>
<informaltable frame='none'>
  <?dbfo keep-together="always" ?>
  <tgroup cols='2' align='left' colsep='0' rowsep='0'>
  <colspec colwidth='0.3*' colname='c1'/>
  <colspec colwidth='1.0*' colname='c2'/>
  <tbody>
    <row>
      <entry>ResourceLine</entry>
      <entry>= Comment | IncludeFile | ResourceSpec | &lt;empty line&gt;</entry>
    </row>
    <row>
      <entry>Comment</entry>
      <entry>="!" {&lt;any character except null or newline&gt;}</entry>
    </row>
    <row>
      <entry>IncludeFile</entry>
      <entry>= "#" WhiteSpace "include" WhiteSpace FileName WhiteSpace</entry>
    </row>
    <row>
      <entry>FileName</entry>
      <entry>= &lt;valid filename for operating system&gt;</entry>
    </row>
    <row>
      <entry>ResourceSpec</entry>
      <entry>= WhiteSpace ResourceName WhiteSpace ":" WhiteSpace Value</entry>
    </row>
    <row>
      <entry>ResourceName</entry>
      <entry>= [Binding] {Component Binding} ComponentName</entry>
    </row>
    <row>
      <entry>Binding</entry>
      <entry>="." | "*"</entry>
    </row>
    <row>
      <entry>WhiteSpace</entry>
      <entry>= {&lt;space> | &lt;horizontal tab&gt;}</entry>
    </row>
    <row>
      <entry>Component</entry>
      <entry>= "?" | ComponentName</entry>
    </row>
    <row>
      <entry>ComponentName</entry>
      <entry>= NameChar {NameChar}</entry>
    </row>
    <row>
      <entry>NameChar</entry>
      <entry>= "a"-"z" | "A"-"Z" | "0"-"9" | "_" | "-"</entry>
    </row>
    <row>
      <entry>Value</entry>
      <entry>={&lt;any character except null or unescaped newline&gt;}</entry>
    </row>
  </tbody>
  </tgroup>
</informaltable>

<para>
Elements separated by vertical bar (|) are alternatives.
Curly braces ({...}) indicate zero or more repetitions
of the enclosed elements.
Square brackets ([...]) indicate that the enclosed element is optional.
Quotes ("...") are used around literal characters.
</para>

<para>
If the last character on a line is a backslash (\),
that line is assumed to continue on the next line.
</para>

<para>
To allow a Value to begin with whitespace,
the two-character sequence "\<emphasis remap='I'>space</emphasis>" (backslash followed by space)
is recognized and replaced by a space character,
and the two-character sequence "\<emphasis remap='I'>tab</emphasis>"
(backslash followed by horizontal tab)
is recognized and replaced by a horizontal tab character.
</para>
<para>
To allow a Value to contain embedded newline characters,
the two-character sequence "\n" is recognized and replaced by a
newline character.
To allow a Value to be broken across multiple lines in a text file,
the two-character sequence "\<emphasis remap='I'>newline</emphasis>"
(backslash followed by newline) is
recognized and removed from the value.
</para>
<para>
To allow a Value to contain arbitrary character codes,
the four-character sequence "\<emphasis remap='I'>nnn</emphasis>",
where each <emphasis remap='I'>n</emphasis> is a digit character in the range of "0"-"7",
is recognized and replaced with a single byte that contains
the octal value specified by the sequence.
Finally, the two-character sequence "\\" is recognized
and replaced with a single backslash.
</para>
</appendix>