basename String [ Suffix ]
dirname [ Option ] Name

basename 命令读取 String 参数，删除以 /(斜杠) 结尾的前缀以及任何指定的 Suffix 参数，并将剩余的基本文件名称写至标准输出。dirname则相反。

#!/bin/sh  
  
# 跳转到脚本所在目录  
cd $(dirname "$0") || exit 1  
// cd `dirname $0`

NAME
       basename - strip directory and suffix from filenames

SYNOPSIS
       basename NAME [SUFFIX]
       basename OPTION... NAME...

DESCRIPTION
       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; implies -a

       -z, --zero
              end each output line with NUL, not 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"

NAME
       dirname - strip last component from file name

SYNOPSIS
       dirname [OPTION] NAME...

DESCRIPTION
       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
              end each output line with NUL, not 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
              -> "."