ispell(interactive spelling checking)
ispell(interactive spelling checking)功能说明：拼字检查程序。
语 法：ispell [-aAbBClmMnNPStVx][-d<字典文件>][-L<行数>][-p<字典文件>][-w<非字母字符>][-W<字符串长度>][要检查的文件]
补充说明：ispell预设会使用/usr/lib/ispell/english.hash字典文件来检查文本文件。若在检查的文件中找到字典没有的词汇，ispell会建议使用的词汇，或是让你将新的词汇加入个人字典。
参 数：
-a 当其他程序输出送到ispell时，必须使用此参数。
-A 读取到"&Include File&"字符串时，就去检查字符串后所指定文件的内容。
-b 产生备份文件，文件名为.bak。
-B 检查连字错误。
-C 不检查连字错误。
-d<字典文件> 指定字典文件。
-l 从标准输入设备读取字符串，结束后显示拼错的词汇。
-L<行数> 指定内文显示的行数。
-m 自动考虑字尾的变化。
-M 进入ispell后，在画面下方显示指令的按键。
-n 检查的文件为noff或troff的格式。
-N 进入ispell后，在画面下方不显示指令的按键。
-p<字典文件> 指定个人字典文件。
-P 不考虑字尾变化的情形。
-S 不排序建议取代的词汇。
-t 检查的文件为TeX或LaTeX的格式。
-V 非ANSI标准的字符会以"M-^"的方式来显示。
-w<非字母字符> 检查时，特别挑出含有指定的字符。
-W<字符串长度> 不检查指定长度的词汇。
-x 不要产生备份文件。
ispell
ispell [options] [files]
Compare the words of one or more named files with the system dictionary. Display unrecognized words at the top of the screen, accompanied by possible correct spellings, and allow editing via a series of commands.
Options
Back up original file in filename.bak.
Count two correctly spelled words without a space between them as a spelling error.
Count two correctly spelled words without a space between them as a legitimate compound word.
Search file instead of standard dictionary file.
File is in HTML/XML format.
Suggest combinations of known roots and affixes, even if the result is not known. For example, "generous" and "ly" are known, so "generously" would be suggested as a word, even if it were not in the dictionary.
Expect nroff or troff input file.
Do not guess new words using known roots and affixes. The opposite of -m.
Search file instead of personal dictionary file.
Expect T
E X or LA TE X input file.
Consider chars to be legal, in addition to a-z and A-Z.
Do not back up original file.
Search for missing blanks (resulting in concatenated words) in addition to ordinary misspellings.
Do not produce error messages in response to concatenated words.
Show number lines of context.
List interactive commands at bottom of screen.
Suppress printing of interactive commands.
Do not attempt to suggest more root/affix combinations.
Sort suggested replacements by likelihood that they are correct.
Expect all files to be formatted by type.
Never consider words that are n characters or fewer to be misspelled.
Use hat notation (^L) to display control characters, and M- to display characters with the high bit set.
Interactive commands
Display help screen.
Accept the word in this instance.
Replace with suggested word that corresponds to number.
Invoke shell and execute command in it. Prompt before exiting.
Accept word as correctly spelled, but do not add it to personal dictionary.
Accept word and add it (with any current capitalization) to personal dictionary.
Search system dictionary for words.
Exit without saving.
Replace word.
Accept word and add lowercase version of it to personal dictionary.
Skip to the next file, saving changes.
Redraw screen.
Suspend ispell.