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diff --git a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-errstruct.html b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-errstruct.html new file mode 100644 index 00000000000..d7dcb5d23d5 --- /dev/null +++ b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-errstruct.html @@ -0,0 +1,75 @@ +<head> +<title>UK TeX FAQ -- question label errstruct</title> +</head><body> +<h3>The structure of TeX error messages</h3> +<p>TeX's error messages are reminiscent of the time when TeX itself +was conceived (the 1970s): they're not terribly user-friendly, though +they do contain all the information that TeX can offer, usually in +a pretty concise way. +<p>TeX's error reports all have the same structure: +<ul> +<li> An error message +<li> Some 'context' +<li> An error prompt +</ul> +The error message will relate to the <em>TeX</em> condition that is +causing a problem. Sadly, in the case of complex macro packages such +as LaTeX, the underlying TeX problem may be superficially +difficult to relate to the actual problem in the "higher-level" +macros. Many LaTeX-detected problems manifest themselves as +'generic' errors, with error text provided by LaTeX itself (or by a +LaTeX class or package). +<p>The context of the error is a stylised representation of what TeX +was doing at the point that it detected the error. As noted in +<a href="FAQ-erroradvice.html">approaching errors</a>, a macro package +can tell TeX how much context to display, and the user may need to +undo what the package has done. Each line of context is split at the +point of the error; if the error <em>actually</em> occurred in a macro +called from the present line, the break is at the point of the call. +(If the called object is defined with arguments, the "point of call" +is after all the arguments have been scanned.) For example: +<pre> +\blah and so on +</pre> +produces the error report +<pre> +! Undefined control sequence. +l.4 \blah + and so on +</pre> +while: +<pre> +\newcommand{\blah}[1]{\bleah #1} +\blah{to you}, folks +</pre> +produces the error report +<pre> +! Undefined control sequence. +\blah #1->\bleah + #1 +l.5 \blah{to you} + , folks +</pre> +If the argument itself is in error, we will see things such as +<pre> +\newcommand{\blah}[1]{#1 to you} +\blah{\bleah}, folks +</pre> +producing +<pre> +! Undefined control sequence. +<argument> \bleah + +l.5 \blah{\bleah} + , folks +</pre> +<p>The prompt accepts single-character commands: the list of what's +available may be had by typing <code>?</code>. One immediately valuable +command is <code>h</code>, which gives you an expansion of TeXs original +précis message, sometimes accompanied by a hint on what to do to +work round the problem in the short term. If you simply type 'return' +(or whatever else your system uses to signal the end of a line) at the +prompt, TeX will attempt to carry on (often with rather little +success). +<p><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=errstruct">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=errstruct</a> +</body> |