How has the application / write permissions data / local / tmp directory

Recently doing a project needs to be applied to a program (such as testcmd) into / data / local / tmp execution.
I will testcmd on assets, then the program getAssets (). Open the file read and write to / data / local / tmp, suggesting that there is no write permissions.
How do you make application with this permission can be achieved?

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Reply:
Plant root and then use chmod to modify / data / local / tmp directory permissions on it
Reply:
There is no other way ah? To support had no root
Reply:
Applications can be written to the directory or what? I just want to find a place to store and run the program.
/ Under data / data / com.myapp / find a catalog I found a machine can create new files, and some can not.

Depressed ah
Reply:
Look:
root @ android :/ data / local # ls-l
drwxrwx - x shell shell 2011-01-01 11:00 tmp
root @ android :/ data / local #
It is a shell group, add your program so that the group has read and write permissions on the shell on it.