#!/path/to/shell [ argument ]

1. #!/path/to/shell[ argument ]
   
2. where /path/to/shell might be/bin/sh,/usr/local/bin/bash
   
3. This line is only interpreted by the operating system. Thatis,
   
4. if a shell script (test.sh)is executable and run from the
   
5. command line by typing its name and giving the script as an
   
6. argument, as in
   
7. $ sh test.sh
   
8. then sh interprets test.sh.For sh, the shebang lineis simply a
   
9. comment, andis ignored $ sh test.sh
   
10. 选择的解释器
    
11. echo $SHELL