<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> <HTML> <HEAD> <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <META name="GENERATOR" content="hevea 1.06-7 of 2001-11-14"> <TITLE> Character input/output </TITLE> </HEAD> <BODY TEXT=black BGCOLOR=white> <A HREF="manual034.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual036.html"><IMG SRC ="next_motif.gif" ALT="Next"></A> <HR> <TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#66dbff"><DIV ALIGN=center><TABLE> <TR><TD><FONT SIZE=4><B><A NAME="htoc139">7.12</A></B></FONT></TD> <TD WIDTH="100%" ALIGN=center><FONT SIZE=4><B>Character input/output</B></FONT></TD> </TR></TABLE></DIV></TD> </TR></TABLE><UL> <LI><A HREF="manual035.html#toc106"> <TT>get_char/2</TT>, <TT>get_char/1</TT>, <TT>get_code/1</TT>, <TT>get_code/2</TT></A> <LI><A HREF="manual035.html#toc107"> <TT>get_key/2</TT>, <TT>get_key/1</TT> <TT>get_key_no_echo/2</TT>, <TT>get_key_no_echo/1</TT></A> <LI><A HREF="manual035.html#toc108"> <TT>peek_char/2</TT>, <TT>peek_char/1</TT>, <TT>peek_code/1</TT>, <TT>peek_code/2</TT></A> <LI><A HREF="manual035.html#toc109"> <TT>unget_char/2</TT>, <TT>unget_char/1</TT>, <TT>unget_code/2</TT>, <TT>unget_code/1</TT></A> <LI><A HREF="manual035.html#toc110"> <TT>put_char/2</TT>, <TT>put_char/1</TT>, <TT>put_code/1</TT>, <TT>put_code/2</TT>, <TT>nl/1</TT>, <TT>nl/0</TT></A> </UL> These built-in predicates enable a single character or character code to be input from and output to a text stream. The atom <TT>end_of_file</TT> is returned as character to indicate the end-of-file. <TT>-1</TT> is returned as character code to indicate the end-of-file.<BR> <BR> <A NAME="toc106"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc140">7.12.1</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>get_char/2</TT>, <TT>get_char/1</TT>, <TT>get_code/1</TT>, <TT>get_code/2</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="get-char/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> get_char(+stream_or_alias, ?in_character)<BR> get_char(?in_character)<BR> get_code(+stream_or_alias, ?in_character_code)<BR> get_code(?in_character_code)</TT></DL> <B>Description</B><BR> <BR> <TT>get_char(SorA, Char)</TT> succeeds if <TT>Char</TT> unifies with the next character read from the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <TT>get_code/2</TT> is similar to <TT>get_char/2</TT> but deals with character codes.<BR> <BR> <TT>get_char/1</TT> and <TT>get_code/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is neither a variable nor an in-character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(in_character, Char)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>The entity input from the stream is not a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is an integer but not an in-character code</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(in_character_code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicates.<BR> <BR> <A NAME="toc107"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc141">7.12.2</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>get_key/2</TT>, <TT>get_key/1</TT> <TT>get_key_no_echo/2</TT>, <TT>get_key_no_echo/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> get_key(+stream_or_alias, ?integer)<BR> get_key(?integer)<BR> get_key_no_echo(+stream_or_alias, ?integer)<BR> get_key_no_echo(?integer)</TT></DL> <B>Description</B><BR> <BR> <TT>get_key(Code, SorA)</TT> succeeds if <TT>Code</TT> unifies with the character code of the next key read from the stream associated with the stream-term or alias <TT>SorA</TT>. It is intended to read a single key from the keyboard (thus <TT>SorA</TT> should refer to current input stream). No buffering is performed (a character is read as soon as available) and function keys can also be read (in that case, <TT>Code</TT> is an integer > 255). The read character is echoed if it is printable. <BR> <BR> This facility is only possible if the <TT>linedit</TT> facility has been installed (section <A HREF="manual006.html#The-line-editor">3.2.5</A>) otherwise <TT>get_key/2</TT> behaves similarly to <TT>get_code/2</TT> (section <A HREF="#get-char/2">7.12.1</A>) (the code of the first character is returned) but also pumps remaining characters until a character < space (0x20) is read (in particular RETURN). The same behavior occurs if <TT>SorA</TT> does not refer to the current input stream or if this stream is not attached to a terminal.<BR> <BR> <TT>get_key_no_echo/2</TT> behaves similarly to <TT>get_key/2</TT> except that the read character is not echoed.<BR> <BR> <TT>get_key/1</TT> and <TT>get_key_no_echo/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates.<BR> <BR> <A NAME="toc108"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc142">7.12.3</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>peek_char/2</TT>, <TT>peek_char/1</TT>, <TT>peek_code/1</TT>, <TT>peek_code/2</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> peek_char(+stream_or_alias, ?in_character)<BR> peek_char(?in_character)<BR> peek_code(+stream_or_alias, ?in_character_code)<BR> peek_code(?in_character_code)</TT></DL> <B>Description</B><BR> <BR> <TT>peek_char(SorA, Char)</TT> succeeds if <TT>Char</TT> unifies with the next character that will be read from the stream associated with the stream-term or alias <TT>SorA</TT>. The character is not read.<BR> <BR> <TT>peek_code/2</TT> is similar to <TT>peek_char/2</TT> but deals with character codes.<BR> <BR> <TT>peek_char/1</TT> and <TT>peek_code/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is neither a variable nor an in-character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(in_character, Char)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>The entity input from the stream is not a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is an integer but not an in-character code</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(in_character_code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicates.<BR> <BR> <A NAME="toc109"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc143">7.12.4</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>unget_char/2</TT>, <TT>unget_char/1</TT>, <TT>unget_code/2</TT>, <TT>unget_code/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> unget_char(+stream_or_alias, +character)<BR> unget_char(+character)<BR> unget_code(+stream_or_alias, +character_code)<BR> unget_code(+character_code)</TT></DL> <B>Description</B><BR> <BR> <TT>unget_char(SorA, Char)</TT> pushes back <TT>Char</TT> onto the stream associated with the stream-term or alias <TT>SorA</TT>. <TT>Char</TT> will be the next character read by <TT>get_char/2</TT>. The maximum number of characters that can be cumulatively pushed back is given by the <TT>max_unget</TT> Prolog flag (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>).<BR> <BR> <TT>unget_code/2</TT> is similar to <TT>unget_char/2</TT> but deals with character codes.<BR> <BR> <TT>unget_char/1</TT> and <TT>unget_code/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, Char)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is an integer but not a character code</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character_code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates.<BR> <BR> <A NAME="toc110"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc144">7.12.5</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>put_char/2</TT>, <TT>put_char/1</TT>, <TT>put_code/1</TT>, <TT>put_code/2</TT>, <TT>nl/1</TT>, <TT>nl/0</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="put-char/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> put_char(+stream_or_alias, +character)<BR> put_char(+character)<BR> put_code(+stream_or_alias, +character_code)<BR> put_code(+character_code)<BR> nl(+stream_or_alias)<BR> nl</TT></DL> <B>Description</B><BR> <BR> <TT>put_char(SorA, Char)</TT> writes <TT>Char</TT> onto the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <TT>put_code/2</TT> is similar to <TT>put_char/2</TT> but deals with character codes.<BR> <BR> <TT>nl(SorA)</TT> writes a new-line character onto the stream associated with the stream-term or alias <TT>SorA</TT>. This is equivalent to <TT>put_char(SorA, '\n')</TT>.<BR> <BR> <TT>put_char/1</TT>, <TT>put_code/1</TT> and <TT>nl/0</TT> apply to the current output stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Char</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, Char)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an input stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Code</TT> is an integer but not a character code</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character_code)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicates.<BR> <BR> <HR SIZE=2> Copyright (C) 1999-2002 Daniel Diaz <BR> <BR> Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved. <BR> <BR> <A HREF="index.html#copyright">More about the copyright</A> <HR> <A HREF="manual034.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual036.html"><IMG SRC ="next_motif.gif" ALT="Next"></A> </BODY> </HTML>