用法：wc [选项]… [文件]…
或：wc [选项]… –files0-from=F
Print newline, word, and byte counts for each FILE, and a total line if
more than one FILE is specified. With no FILE, or when FILE is -,
read standard input. A word is a non-zero-length sequence of characters
delimited by white space.
The options below may be used to select which counts are printed, always in
the following order: newline, word, character, byte, maximum line length.
-c, –bytes print the byte counts
-m, –chars print the character counts
-l, –lines print the newline counts
–files0-from=文件 从指定文件读取以NUL 终止的名称，如果该文件被
指定为”-“则从标准输入读文件名
-L, –max-line-length 显示最长行的长度
-w, –words 显示单词计数
–help 显示此帮助信息并退出
–version 显示版本信息并退出
