1）问题现象：
在ubuntu下执行以下脚本( while_count),报错：
-bash: ./while_count: /bin/bash: bad interpreter: Text file busy
2）问题原因：
This happens because the script file is open for writing, possibly by a rogue process which has not terminated.
3）解决办法：
Solution: Check what process is still accessing the file, and terminate it.
Run lsof (list open files command) on the script name:
lsof | grep while-count
cat 17653 me 1w REG 8,1 148 181517 /home/me/test/while-count
kill -9 17653
Now try running the script again. It works now.