85 lines
2.6 KiB
HTML
85 lines
2.6 KiB
HTML
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<! $Id: File.3,v 1.3 2019/09/09 22:35:37 stolcke Exp $>
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<HTML>
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<HEADER>
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<TITLE>File</TITLE>
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<BODY>
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<H1>File</H1>
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<H2> NAME </H2>
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File - Wrapper for stdio streams
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<H2> SYNOPSIS </H2>
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<PRE>
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<B> #include <File.h> </B>
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</PRE>
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<H2> DESCRIPTION </H2>
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The
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<B> File </B>
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class provides a simple wrapper around stdio streams for use
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with C++.
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It provides two kinds of convenience:
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Firstly, constructors and destructors manage opening and closing of the stream.
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The stream is checked for errors on closing, and the default behavior
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is to exit() with an error message if a problem was found.
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Secondly, the getline() method can be used for line-oriented input.
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It strips comments and keeps track of input line
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numbers for error reporting.
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<H2> CLASS MEMBERS </H2>
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<DL>
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<DT><B> File(const char *<I>name</I>, const char *<I>mode</I>, int <I>exitOnError</I> = 1) </B>
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<DD>
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<DT><B> File(FILE *<I>fp</I> = 0, int <I>exitOnError</I> = 1) </B>
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<DD>
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A File object can be initialized with either a filename or an existing
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stdio stream.
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In the first case, the file is opened according to <I>mode</I>
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(as if by
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<A HREF="fopen.3.html">fopen(3)</A>).
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The <I>exitOnError</I> flag determines whether I/O errors should be treated
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as fatal.
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<DT><B> ~File() </B>
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<DD>
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Destroying a File object implies closing the associated stream.
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<DT><B> char *getline() </B>
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<DD>
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Returns the next line from the input, stored in a static buffer of
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up to <B>maxLineLength</B> characters.
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Empty lines and lines starting with <B>#</B> are skipped.
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<DT><B> int close() </B>
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<DD>
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Closes the stream without destroying the File object.
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Returns non-zero is an error condition occurs.
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<DT><B> int error() </B>
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<DD>
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Returns a non-zero value if an error condition occurred on the stream.
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<DT><B> operator FILE *() </B>
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<DD>
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A File object can be cast to <B>FILE *</B> to access the underlying stdio
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stream.
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<DT><B> ostream &position(ostream &<I>stream</I> = cerr) </B>
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<DD>
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Outputs the current line number on <I>stream</I>.
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The <I>stream</I> is returned so it can be used as the left operand
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of the <B><<</B> operator.
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<DT><B> const char *name </B>
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<DD>
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The filename used in creating the File object.
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<DT><B> const unsigned lineno </B>
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<DD>
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The current line number as maintained by <B>getline()</B>.
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<DT><B> int exitOnError </B>
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<DD>
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When set to <B>true</B> this causes errors on the
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stream to be handled by program termination (after printing an
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error message).
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</DD>
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</DL>
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<H2> SEE ALSO </H2>
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<A HREF="stdio.3.html">stdio(3)</A>
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<H2> BUGS </H2>
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Many other potentially useful functions are not provided (yet).
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<H2> AUTHOR </H2>
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Andreas Stolcke <stolcke@icsi.berkeley.edu>
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<BR>
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Copyright (c) 1995-1996 SRI International
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</BODY>
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</HTML>
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