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| 11 | <title>Boost Filesystem convenience.hpp Header</title> |
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| 14 | <body bgcolor="#FFFFFF"> |
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| 15 | |
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| 16 | <h1> |
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| 17 | <img border="0" src="../../../boost.png" align="center" width="277" height="86"><a href="../../../boost/filesystem/convenience.hpp">boost/filesystem/convenience.hpp</a></h1> |
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| 18 | |
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| 19 | <p>Header <a href="../../../boost/filesystem/convenience.hpp">convenience.hpp</a> |
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| 20 | provides convenience functions that combine lower-level functions in useful |
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| 21 | ways.</p> |
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| 22 | |
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| 23 | <h2>Contents</h2> |
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| 24 | |
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| 25 | <dl class="index"> |
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| 26 | <dt><a href="#create_directories">create_directories</a> |
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| 27 | <dt><a href="#extension">extension</a> |
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| 28 | <dt><a href="#basename">basename</a> |
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| 29 | <dt><a href="#change_extension">change_extension</a> |
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| 30 | </dl> |
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| 31 | |
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| 32 | <h2 id="create_directories">create_directories</h2> |
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| 33 | |
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| 34 | <blockquote> |
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| 35 | |
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| 36 | <p><code>bool create_directories( const path & ph );</code></p> |
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| 37 | |
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| 38 | <p><b>Precondition:</b> <code>ph.empty() || <br> |
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| 39 | forall p: p == ph || is_parent(p, ph): is_directory(p) || !exists( p )</code> |
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| 40 | </p> |
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| 41 | <p><b>Returns:</b> The value of <code>!exists(ph)</code> prior to the |
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| 42 | establishment of the postcondition.</p> |
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| 43 | |
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| 44 | <p><b>Postcondition:</b> <code>exists(ph) && is_directory(ph)</code></p> |
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| 45 | |
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| 46 | <p><b>Throws:</b> <code>exists(ph) && !is_directory(ph)</code></p> |
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| 47 | |
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| 48 | <p>Contributed by Vladimir Prus.</p> |
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| 49 | |
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| 50 | </blockquote> |
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| 51 | |
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| 52 | <h2 id="extension">extension</h2> |
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| 53 | |
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| 54 | <blockquote> |
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| 55 | |
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| 56 | <p><code>std::string extension( const path & ph );</code></p> |
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| 57 | |
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| 58 | <p><b>Returns:</b> if <code>ph.leaf()</code> contains a dot ('.'), |
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| 59 | returns the substring of <code>ph.leaf()</code> starting from the last dot and |
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| 60 | ending at the string's end. Otherwise, returns empty string. |
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| 61 | <p><b>Rationale:</b> <ul> |
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| 62 | <li>The dot is included in the return value so that it's |
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| 63 | possible to tell if extension is empty or absent. |
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| 64 | <li>It was noted that this definition of extension is probably not sufficient |
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| 65 | when using <a href="http://support.microsoft.com/kb/105763">Alternate Data Streams</a> — |
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| 66 | a filesystem feature specific to NTFS. However, semantics in this case were not |
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| 67 | clear, and the current behavior is still quite useful. |
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| 68 | </ul> |
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| 69 | <p><b>Acknowlegements:</b> Carl Daniel and Pavel Vozenilek noticed and |
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| 70 | discussed the ADS issue. |
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| 71 | |
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| 72 | <p>Contributed by Vladimir Prus.</p> |
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| 73 | |
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| 74 | </blockquote> |
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| 75 | |
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| 76 | <h2 id="basename">basename</h2> |
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| 77 | |
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| 78 | <blockquote> |
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| 79 | |
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| 80 | <p><code>std::string basename( const path & ph );</code></p> |
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| 81 | |
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| 82 | <p><b>Returns:</b> if <code>ph.leaf()</code> contains a dot ('.'), |
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| 83 | returns the substring of <code>ph.leaf()</code> starting from beginning and |
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| 84 | ending at the last dot (the dot is not included). Otherwise, returns |
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| 85 | <code>ph.leaf()</code> |
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| 86 | |
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| 87 | </p> |
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| 88 | |
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| 89 | <p>Contributed by Vladimir Prus.</p> |
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| 90 | |
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| 91 | </blockquote> |
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| 92 | |
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| 93 | <h2 id="change_extension">change_extension</h2> |
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| 94 | |
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| 95 | <blockquote> |
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| 96 | |
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| 97 | <p><code>path change_extension( const path & ph, const std::string & new_extension );</code></p> |
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| 98 | |
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| 99 | <p><b>Postcondition:</b> <code>basename(return_value) == basename(ph) |
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| 100 | && extension(return_value) == new_extension</code> |
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| 101 | <p><b>Note:</b> It follows from the semantic of <code>extension</code> that |
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| 102 | <code>new_extension</code> should include dot to achieve reasonable results. |
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| 103 | </p> |
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| 104 | <p><b>Rationale:</b> Previously, this functions had |
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| 105 | <code>!ph.leaf().empty()</code> as precondition. It's not clear if it was |
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| 106 | right or wrong. Changing extension of an empty path looks pointless. On the |
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| 107 | other hand, the value of precondition was questionable: one would better place such |
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| 108 | checks at the points where paths are entered by the user. Current decision |
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| 109 | is to drop the precondition.</p> |
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| 110 | |
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| 111 | <p>Contributed by Vladimir Prus.</p> |
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| 112 | |
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| 113 | </blockquote> |
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| 114 | |
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| 115 | |
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| 116 | |
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| 117 | <hr> |
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| 118 | <p>Revised |
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| 119 | <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->11 March, 2004<!--webbot bot="Timestamp" endspan i-checksum="28863" --></p> |
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| 120 | <p>© Copyright Vladimir Prus, 2003</p> |
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| 121 | <p> Use, modification, and distribution are subject to the Boost Software |
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| 122 | License, Version 1.0. (See accompanying file <a href="../../../LICENSE_1_0.txt"> |
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| 123 | LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt"> |
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| 124 | www.boost.org/LICENSE_1_0.txt</a>)</p> |
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| 125 | |
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| 126 | </body> |
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| 127 | |
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| 128 | </html> |
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