file.html

IEEE 1003.1-2003, Single Unix Specification v3

</td>
<td align="left">
<p class="tent">1</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Socket</p>
</td>
<td align="left">
<p class="tent">socket</p>
</td>
<td align="left">
<p class="tent">1</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Symbolic link</p>
</td>
<td align="left">
<p class="tent">symbolic link to</p>
</td>
<td align="left">
<p class="tent">1</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Regular file</p>
</td>
<td align="left">
<p class="tent">regular file</p>
</td>
<td align="left">
<p class="tent">1,2</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Empty regular file</p>
</td>
<td align="left">
<p class="tent">empty</p>
</td>
<td align="left">
<p class="tent">3</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Regular file that cannot be read</p>
</td>
<td align="left">
<p class="tent">cannot open</p>
</td>
<td align="left">
<p class="tent">3</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Executable binary</p>
</td>
<td align="left">
<p class="tent">executable</p>
</td>
<td align="left">
<p class="tent">4,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>ar</i> archive library (see <i>ar</i>)</p>
</td>
<td align="left">
<p class="tent">archive</p>
</td>
<td align="left">
<p class="tent">4,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Extended <i>cpio</i> format (see <i>pax</i>)</p>
</td>
<td align="left">
<p class="tent">cpio archive</p>
</td>
<td align="left">
<p class="tent">4,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Extended <i>tar</i> format (see <b>ustar</b> in <i>pax</i>)</p>
</td>
<td align="left">
<p class="tent">tar archive</p>
</td>
<td align="left">
<p class="tent">4,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Shell script</p>
</td>
<td align="left">
<p class="tent">commands text</p>
</td>
<td align="left">
<p class="tent">5,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">C-language source</p>
</td>
<td align="left">
<p class="tent">c program text</p>
</td>
<td align="left">
<p class="tent">5,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">FORTRAN source</p>
</td>
<td align="left">
<p class="tent">fortran program text</p>
</td>
<td align="left">
<p class="tent">5,6</p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent">Regular file whose type cannot be determined</p>
</td>
<td align="left">
<p class="tent">data</p>
</td>
<td align="left">
<p class="tent">&nbsp;</p>
</td>
</tr>
</table>
</center>

<basefont size="2"> 

<dl>
<dt><b>Notes:</b></dt>

<dd>
<ol>
<li>
<p>This is a file type test.</p>
</li>

<li>
<p>This test is applied only if the <b>-i</b> option is specified.</p>
</li>

<li>
<p>This test is applied only if the <b>-i</b> option is not specified.</p>
</li>

<li>
<p>This is a position-sensitive default system test.</p>
</li>

<li>
<p>This is a context-sensitive default system test.</p>
</li>

<li>
<p>Position-sensitive default system tests and context-sensitive default system tests are not applied if the <b>-M</b> option is
specified unless the <b>-d</b> option is also specified.</p>
</li>
</ol>
</dd>
</dl>

<basefont size="3"> 

<p>In the POSIX locale, if <i>file</i> is identified as a symbolic link (see the <b>-h</b> option), the following alternative
output format shall be used:</p>

<pre>
<tt>"%s: %s %s\n", &lt;</tt><i>file</i><tt>&gt;, &lt;</tt><i>type</i><tt>&gt;, &lt;</tt><i>contents of link</i><tt>&gt;"
</tt>
</pre>

<p>If the file named by the <i>file</i> operand does not exist, cannot be read, or the type of the file named by the <i>file</i>
operand cannot be determined, this shall not be considered an error that affects the exit status.</p>
</blockquote>

<h4><a name="tag_04_54_11"></a>STDERR</h4>

<blockquote>
<p>The standard error shall be used only for diagnostic messages.</p>
</blockquote>

<h4><a name="tag_04_54_12"></a>OUTPUT FILES</h4>

<blockquote>
<p>None.</p>
</blockquote>

<h4><a name="tag_04_54_13"></a>EXTENDED DESCRIPTION</h4>

<blockquote>
<p>A file specified as an option-argument to the <b>-m</b> or <b>-M</b> options shall contain one position-sensitive test per line,
which shall be applied to the file. If the test succeeds, the message field of the line shall be printed and no further tests shall
be applied, with the exception that tests on immediately following lines beginning with a single <tt>'&gt;'</tt> character shall be
applied.</p>

<p>Each line shall be composed of the following four &lt;blank&gt;-separated fields:</p>

<dl compact>
<dt><i>offset</i></dt>

<dd>An unsigned number (optionally preceded by a single <tt>'&gt;'</tt> character) specifying the <i>offset</i>, in bytes, of the
value in the file that is to be compared against the <i>value</i> field of the line. If the file is shorter than the specified
offset, the test shall fail. 

<p>If the <i>offset</i> begins with the character <tt>'&gt;'</tt> , the test contained in the line shall not be applied to the file
unless the test on the last line for which the <i>offset</i> did not begin with a <tt>'&gt;'</tt> was successful. By default, the
<i>offset</i> shall be interpreted as an unsigned decimal number. With a leading 0x or 0X, the <i>offset</i> shall be interpreted
as a hexadecimal number; otherwise, with a leading 0, the <i>offset</i> shall be interpreted as an octal number.</p>
</dd>

<dt><i>type</i></dt>

<dd>The type of the value in the file to be tested. The type shall consist of the type specification characters <tt>c</tt> ,
<tt>d</tt> , <tt>f</tt> , <tt>s</tt> , and <tt>u</tt> , specifying character, signed decimal, floating point, string, and unsigned
decimal, respectively. 

<p>The <i>type</i> string shall be interpreted as the bytes from the file starting at the specified <i>offset</i> and including the
same number of bytes specified by the <i>value</i> field. If insufficient bytes remain in the file past the <i>offset</i> to match
the <i>value</i> field, the test shall fail.</p>

<p>The type specification characters <tt>d</tt> , <tt>f</tt> , and <tt>u</tt> can be followed by an optional unsigned decimal
integer that specifies the number of bytes represented by the type. The type specification character <tt>f</tt> can be followed by
an optional <tt>F</tt> , <tt>D</tt> , or <tt>L</tt> , indicating that the value is of type <b>float</b>, <b>double</b>, or <b>long
double</b>, respectively. The type specification characters <tt>d</tt> and <tt>u</tt> can be followed by an optional <tt>C</tt> ,
<tt>S</tt> , <tt>I</tt> , or <tt>L</tt> , indicating that the value is of type <b>char</b>, <b>short</b>, <b>int</b>, or
<b>long</b>, respectively.</p>

<p>The default number of bytes represented by the type specifiers <tt>d</tt> , <tt>f</tt> , and <tt>u</tt> shall correspond to
their respective C-language types as follows. If the system claims conformance to the C-Language Development Utilities option,
those specifiers shall correspond to the default sizes used in the <a href="../utilities/c99.html"><i>c99</i></a> utility.
Otherwise, the default sizes shall be implementation-defined.</p>

<p>For the type specifier characters <tt>d</tt> and <tt>u</tt> , the default number of bytes shall correspond to the size of a
basic integer type of the implementation. For these specifier characters, the implementation shall support values of the optional
number of bytes to be converted corresponding to the number of bytes in the C-language types <b>char</b>, <b>short</b>, <b>int</b>,
or <b>long</b>. These numbers can also be specified by an application as the characters <tt>C</tt> , <tt>S</tt> , <tt>I</tt> , and
<tt>L</tt> , respectively. The byte order used when interpreting numeric values is implementation-defined, but shall correspond to
the order in which a constant of the corresponding type is stored in memory on the system.</p>

<p>For the type specifier <tt>f</tt> , the default number of bytes shall correspond to the number of bytes in the basic double
precision floating-point data type of the underlying implementation. The implementation shall support values of the optional number
of bytes to be converted corresponding to the number of bytes in the C-language types <b>float</b>, <b>double</b>, and <b>long