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| <h3 class="section">14.10 Making Special Files</h3> |
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| <p><a name="index-creating-special-files-1596"></a><a name="index-special-files-1597"></a> |
| The <code>mknod</code> function is the primitive for making special files, |
| such as files that correspond to devices. The GNU library includes |
| this function for compatibility with BSD. |
| |
| <p>The prototype for <code>mknod</code> is declared in <samp><span class="file">sys/stat.h</span></samp>. |
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| — Function: int <b>mknod</b> (<var>const char *filename, int mode, int dev</var>)<var><a name="index-mknod-1599"></a></var><br> |
| <blockquote><p>The <code>mknod</code> function makes a special file with name <var>filename</var>. |
| The <var>mode</var> specifies the mode of the file, and may include the various |
| special file bits, such as <code>S_IFCHR</code> (for a character special file) |
| or <code>S_IFBLK</code> (for a block special file). See <a href="Testing-File-Type.html#Testing-File-Type">Testing File Type</a>. |
| |
| <p>The <var>dev</var> argument specifies which device the special file refers to. |
| Its exact interpretation depends on the kind of special file being created. |
| |
| <p>The return value is <code>0</code> on success and <code>-1</code> on error. In addition |
| to the usual file name errors (see <a href="File-Name-Errors.html#File-Name-Errors">File Name Errors</a>), the |
| following <code>errno</code> error conditions are defined for this function: |
| |
| <dl> |
| <dt><code>EPERM</code><dd>The calling process is not privileged. Only the superuser can create |
| special files. |
| |
| <br><dt><code>ENOSPC</code><dd>The directory or file system that would contain the new file is full |
| and cannot be extended. |
| |
| <br><dt><code>EROFS</code><dd>The directory containing the new file can't be modified because it's on |
| a read-only file system. |
| |
| <br><dt><code>EEXIST</code><dd>There is already a file named <var>filename</var>. If you want to replace |
| this file, you must remove the old file explicitly first. |
| </dl> |
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