导致“紧急停止”错误的最短代码

Question 1

\def\a{a\a}\a

编辑：简短版本，正如 Bruno 所建议的：

\def~{~~}~

得出I can't go on meeting you like this：

\halign{#&&#\cr\multispan{300}}

结果是This can't happen：

\halign{#&&#\cr\multispan{300}\cr}

Answer

\def\a{a\a}\a

编辑：简短版本，正如 Bruno 所建议的：

\def~{~~}~

得出I can't go on meeting you like this：

\halign{#&&#\cr\multispan{300}}

结果是This can't happen：

\halign{#&&#\cr\multispan{300}\cr}

Question 2

一个仅由以下内容组成的文件^H（IIRC 唯一一个在 LaTeX 中默认情况下 catcode 无效的字符）将执行此操作：

[1 1016] ~/temp % echo -e '\b' | latex
This is pdfTeX, Version 3.1415926-2.3-1.40.12 (TeX Live 2011)
**entering extended mode
! Text line contains an invalid character.
<*> ^^H

? 
! Emergency stop.
<*> ^^H

No pages of output.
Transcript written on texput.log.
[1 1017] ~/temp %

Answer

一个仅由以下内容组成的文件^H（IIRC 唯一一个在 LaTeX 中默认情况下 catcode 无效的字符）将执行此操作：

[1 1016] ~/temp % echo -e '\b' | latex
This is pdfTeX, Version 3.1415926-2.3-1.40.12 (TeX Live 2011)
**entering extended mode
! Text line contains an invalid character.
<*> ^^H

? 
! Emergency stop.
<*> ^^H

No pages of output.
Transcript written on texput.log.
[1 1017] ~/temp %

Question 3

以下是日志：

This is TeX, Version 3.1415926 (TeX Live 2011) (format=tex 2011.8.28)  14 OCT 2011 11:17
**short
(./short.tex)
! Emergency stop.
<*> short

*** (job aborted, no legal \end found)

No pages of output.

如果允许跑步-interaction=batchmode那么我赢了：试试看

touch inexistent.tex
tex -interaction=batchmode inexistent

你会得到

This is TeX, Version 3.1415926 (TeX Live 2011) (format=tex 2011.8.28)  14 OCT 2011 11:25
**inexistent.tex
(./inexistent.tex)
! Emergency stop.
<*> inexistent.tex

*** (job aborted, no legal \end found)

No pages of output.

要检查的 shell 的输出：

> ls -l inexistent.tex 
-rw-r--r--  1 enricomb  staff  0 Oct 14 11:25 inexistent.tex

Answer