40 lines
2.3 KiB
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40 lines
2.3 KiB
HTML
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<HTML><HEAD><TITLE>Tcl Built-In Commands - gets manual page</TITLE></HEAD><BODY>
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<H3><A NAME="M2">NAME</A></H3>
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gets - Read a line from a channel
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<H3><A NAME="M3">SYNOPSIS</A></H3>
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<B>gets </B><I>channelId</I> ?<I>varName</I>?<BR>
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<H3><A NAME="M4">DESCRIPTION</A></H3>
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This command reads the next line from <I>channelId</I>, returns everything
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in the line up to (but not including) the end-of-line character(s), and
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discards the end-of-line character(s).
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If <I>varName</I> is omitted the line is returned as the result of the
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command.
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If <I>varName</I> is specified then the line is placed in the variable by
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that name and the return value is a count of the number of characters
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returned.
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<P>
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If end of file occurs while scanning for an end of
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line, the command returns whatever input is available up to the end of file.
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If <I>channelId</I> is in nonblocking mode and there is not a full
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line of input available, the command returns an empty string and
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does not consume any input.
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If <I>varName</I> is specified and an empty string is returned in
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<I>varName</I> because of end-of-file or because of insufficient
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data in nonblocking mode, then the return count is -1.
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Note that if <I>varName</I> is not specified then the end-of-file
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and no-full-line-available cases can
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produce the same results as if there were an input line consisting
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only of the end-of-line character(s).
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The <B><A HREF="../TkCmd/eof.htm">eof</A></B> and <B><A HREF="../TkCmd/fblocked.htm">fblocked</A></B> commands can be used to distinguish
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these three cases.
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<H3><A NAME="M5">SEE ALSO</A></H3>
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<B><A HREF="../TkCmd/file.htm">file</A></B>, <B><A HREF="../TkCmd/eof.htm">eof</A></B>, <B><A HREF="../TkCmd/fblocked.htm">fblocked</A></B>
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<H3><A NAME="M6">KEYWORDS</A></H3>
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<A href="../Keywords/B.htm#blocking">blocking</A>, <A href="../Keywords/C.htm#channel">channel</A>, <A href="../Keywords/E.htm#end of file">end of file</A>, <A href="../Keywords/E.htm#end of line">end of line</A>, <A href="../Keywords/L.htm#line">line</A>, <A href="../Keywords/N.htm#nonblocking">nonblocking</A>, <A href="../Keywords/R.htm#read">read</A>
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<HR><PRE>
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<A HREF="../copyright.htm">Copyright</A> © 1993 The Regents of the University of California.
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<A HREF="../copyright.htm">Copyright</A> © 1994-1996 Sun Microsystems, Inc.
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<A HREF="../copyright.htm">Copyright</A> © 1995-1997 Roger E. Critchlow Jr.</PRE>
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</BODY></HTML>
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