2、wc [-lwm]
选项与参数：
-l ：仅列出行；
-w ：仅列出多少字(英文单字)；
-m ：多少字符；
3、md5sum
md5sum [OPTION]... [FILE]...
Print or check MD5 (128-bit) checksums.
With no FILE, or when FILE is -, read standard input.
-b, --binary read in binary mode
-c, --check read MD5 sums from the FILEs and check them
-t, --text read in text mode (default)
1)示例
md5sum prime.cpp
md5sum prime.cpp > md5_file
md5sum *.cpp > md5_file
验证：
md5sum -c md5_file
7、basename,dirname
1)Usage: basename NAME [SUFFIX]
or: basename OPTION
Examples:
basename /usr/bin/sort Output "sort".
basename include/stdio.h .h Output "stdio".
2)Usage: dirname NAME
or: dirname OPTION
Examples:
dirname /usr/bin/ Output "/usr".
dirname stdio.h Output ".".
