basename和dirname绝对和相对路径

绝对路径

以正斜杠开始
完整的文件的位置路径
可用于任何想指定一个文件名的时候

相对路径名

不以斜线开始
指定相对于当前工作目录或某目录的位置
可以作为一个简短的形式指定一个文件名
基名：basename
目录名：dirname

[root@localhost ~]# basename
basename: missing operand
Try 'basename --help' for more information.
[root@localhost ~]# basename --help
Usage: basename NAME [SUFFIX]
  or:  basename OPTION... NAME...
Print NAME with any leading directory components removed.
If specified, also remove a trailing SUFFIX.

Mandatory arguments to long options are mandatory for short options too.
  -a, --multiple       support multiple arguments and treat each as a NAME
  -s, --suffix=SUFFIX  remove a trailing SUFFIX
  -z, --zero           separate output with NUL rather than newline
      --help     display this help and exit
      --version  output version information and exit

Examples:
  basename /usr/bin/sort          -> "sort"
  basename include/stdio.h .h     -> "stdio"
  basename -s .h include/stdio.h  -> "stdio"
  basename -a any/str1 any/str2   -> "str1" followed by "str2"

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'basename invocation'
[root@localhost ~]# basename /usr/bin/sort 
sort
[root@localhost ~]# dirname --help
Usage: dirname [OPTION] NAME...
Output each NAME with its last non-slash component and trailing slashes
removed; if NAME contains no /'s, output '.' (meaning the current directory).

  -z, --zero     separate output with NUL rather than newline
      --help     display this help and exit
      --version  output version information and exit

Examples:
  dirname /usr/bin/          -> "/usr"
  dirname dir1/str dir2/str  -> "dir1" followed by "dir2"
  dirname stdio.h            -> "."

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'dirname invocation'
[root@localhost ~]# dirname /usr/bin/
/usr
[root@localhost ~]# dirname dir1/str
dir1
[root@localhost ~]#
[root@localhost ~]# dirname /etc/sysconfig/network-scripts/ifcfg-eth0
/etc/sysconfig/network-scripts
[root@localhost ~]#