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| <h3 class="section">11.1 Input/Output Concepts</h3> |
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| <p>Before you can read or write the contents of a file, you must establish |
| a connection or communications channel to the file. This process is |
| called <dfn>opening</dfn> the file. You can open a file for reading, writing, |
| or both. |
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| The connection to an open file is represented either as a stream or as a |
| file descriptor. You pass this as an argument to the functions that do |
| the actual read or write operations, to tell them which file to operate |
| on. Certain functions expect streams, and others are designed to |
| operate on file descriptors. |
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| <p>When you have finished reading to or writing from the file, you can |
| terminate the connection by <dfn>closing</dfn> the file. Once you have |
| closed a stream or file descriptor, you cannot do any more input or |
| output operations on it. |
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| <li><a accesskey="1" href="Streams-and-File-Descriptors.html#Streams-and-File-Descriptors">Streams and File Descriptors</a>: The GNU Library provides two ways |
| to access the contents of files. |
| <li><a accesskey="2" href="File-Position.html#File-Position">File Position</a>: The number of bytes from the |
| beginning of the file. |
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