📄 xbd_chap10.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2003 The Open Group, All Rights Reserved --><title>Rationale</title></head><body><basefont size="3"> <center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group</font></center><hr size="2" noshade><h3><a name="tag_01_10"></a>Directory Structure and Devices</h3><h4><a name="tag_01_10_01"></a>Directory Structure and Files</h4><p>A description of the historical <b>/usr/tmp</b> was omitted, removing any concept of differences in emphasis between the<b>/</b> and <b>/usr</b> directories. The descriptions of <b>/bin</b>, <b>/usr/bin</b>, <b>/lib</b>, and <b>/usr/lib</b> wereomitted because they are not useful for applications. In an early draft, a distinction was made between system and applicationdirectory usage, but this was not found to be useful.</p><p>The directories <b>/</b> and <b>/dev</b> are included because the notion of a hierarchical directory structure is key to otherinformation presented elsewhere in IEEE Std 1003.1-2001. In early drafts, it was argued that special devices andtemporary files could conceivably be handled without a directory structure on some implementations. For example, the system couldtreat the characters <tt>"/tmp"</tt> as a special token that would store files using some non-POSIX file system structure. Thisnotion was rejected by the standard developers, who required that all the files in this section be implemented via POSIX filesystems.</p><p>The <b>/tmp</b> directory is retained in IEEE Std 1003.1-2001 to accommodate historical applications that assume itsavailability. Implementations are encouraged to provide suitable directory names in the environment variable <i>TMPDIR</i> andapplications are encouraged to use the contents of <i>TMPDIR</i> for creating temporary files.</p><p>The standard files <b>/dev/null</b> and <b>/dev/tty</b> are required to be both readable and writable to allow applications tohave the intended historical access to these files.</p><p>The standard file <b>/dev/console</b> has been added for alignment with the Single UNIX Specification.</p><h4><a name="tag_01_10_02"></a>Output Devices and Terminal Types</h4><p>There is no additional rationale provided for this section.</p><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -