outputting a command to the terminal?

[John Salerno]

Steven Bethard wrote:
> John Salerno wrote:
>> Here's my new project: I want to write a little script that I can type 
>> at the terminal like this:
>>
>> $ scriptname package1 [package2, ...]
>>
>> where scriptname is my module name and any subsequent arguments are 
>> the names of Linux packages to install. Running the script as above 
>> will create this line:
>>
>> sudo aptitude install package1 package2 ...
>>
>> It will run that line at the terminal so the package(s) will be 
>> installed.
>>
>> Now, the extra functionality I want to add (otherwise I would just 
>> install them normally!) is to save the package names to a text file so 
>> I can now the names of programs I've manually installed, if I ever 
>> want to check the list or remove packages.
>>
>> So creating the proper bash command (sudo aptitude install ...) is 
>> easy, and writing the names to a file is easy. But I have two questions:
>>
>> 1. First of all, does Linux keep track of the packages you manually 
>> install? If so, then I won't have to do this at all.
>>
>> 2. Assuming I write this, how do output the bash command to the 
>> terminal? Is there a particular module that Python uses to interact 
>> with the terminal window that I can use to send the install command to 
>> the terminal?
> 
> 
> I don't know the answer to the first bit here, but I think the following 
> should get you most of what you want as far as the second bit is concerned:
> 
> 
> ---------------------------- scriptname.py ----------------------------
> import argparse # http://argparse.python-hosting.com/
> import subprocess
> import sys
> 
> def outputfile(filename):
>     return open(filename, 'w')
> 
> if __name__ == '__main__':
>     # parse the command line arguments
>     parser = argparse.ArgumentParser()
>     parser.add_argument('packages', metavar='package', nargs='+',
>                         help='one of the packages to install')
>     parser.add_argument('--save', type=outputfile, default=sys.stdout,
>                         help='a file to save the package names to')
>     namespace = parser.parse_args()
> 
>     # call the command
>     command = ['sudo', 'aptitude', 'install'] + namespace.packages
>     subprocess.call(command)
> 
>     # write the package name file
>     for package_name in namespace.packages:
>         namespace.save.write('%s\n' % package_name)
> -----------------------------------------------------------------------
> 
> 
> $ scriptname.py -h
> usage: scriptname.py [-h] [--save SAVE] package [package ...]
> 
> positional arguments:
>   package      one of the packages to install
> 
> optional arguments:
>   -h, --help   show this help message and exit
>   --save SAVE  a file to save the package names to
> 
> 
> 
> STeVe

yikes! I'll have to take some time to study this! I appreciate it. :)