python alternative to os.system()

datadriven · 02-25-2005, 09:35 AM

Hey Guys,

say I have this command in a loop where pkg contains the path to a package to be installed on a slackware system

Code:

packages = os.listdir(download_folder)
for pkg in packages:
    cmd = "su -c 'upgradepkg --install-new " + download_folder + "/" + pkg + "'"
    os.system(cmd)

That will prompt for a password and install packages from download_folder

How can I do this in a way where I could prompt for the password and then send the password in where it's needed. I can't seem to get the syntax right to use pipe, and popen tells me that su must be run in a terminal.

Crashed_Again · 02-25-2005, 11:26 AM

You just want to put in your password once and then it installs everything else right? I'd guess that because your in the for loop your getting prompted for the password everytime. Did you try putting the su -c outside of the for loop:

Code:

packages = os.listdir(download_folder)
os.system("su -")
# it will prompt you for your password
for pkg in packages:
    cmd = "upgradepkg --install-new " + download_folder + "/" + pkg
    os.system(cmd)

I haven't tested this out and it may not work but its just a thought.

datadriven · 02-25-2005, 05:49 PM

I'va already done similar things, but that's not what I was looking for. The rest of my program get all user input using dialog. I want to avoid using the console and run the command in a pipe of some type.

johnMG · 02-27-2005, 12:53 AM

Not sure, but maybe this will help:

Code:

import commands
foo = commands.getoutput( 'ls' ) # executed as 2 > &1

The output of running that shell command gets placed into the variable foo, rather than printed to stdout.

Well, it's an alternative to os.system() anyhow.

datadriven · 02-27-2005, 07:42 AM

That's pretty good, but maybe I need to explain myself better. Here's the function I want to modify. It comes from my project getpkg

http://sourceforge.net/projects/getpkg/

What I have:

Code:

def install_downloaded_pkgs(d):
	global download_folder
	global desc_folder
	downloaded = os.listdir(download_folder)
	if len(downloaded) == 0:
		d.infobox("Download folder is empty")
		return
	if len(downloaded) > 0:
		heading = "Choose package(s) to Install"
		maxLen = len(heading)
		downloaded_list = []
		for dl in downloaded:
			if len(dl) > maxLen: maxLen = len(dl)
			downloaded_list.append((dl,"",0))
		inst_choice = d.checklist(heading,downloaded_list,maxLen+12,len(downloaded)+6,len(downloaded))
		if len(inst_choice) > 0:
			print "Installing packages requires root access."
			print "Please enter your password."
			inst_cmd = "su -c 'upgradepkg --install-new"
			for pkg in inst_choice:
				inst_cmd += " " + download_folder + "/" + pkg
			inst_cmd += "'"
			os.system(inst_cmd)
	inst_pkglist = get_installed_pkgs(d)
	os.unlink(inst_path)
	output = open(inst_path,'w')
	for pkg in inst_pkglist:
		output.write(str(pkg) + "\n")
	output.close()
	return

The above code uses a dialog class that I wrote to get all input/output using the linux dialog utility. The only time the program dumps the user back to the console is when installing packages. I want to prompt the user for a password and show the user the package description file while the file is being installed.

What I want.

Code:

def install_downloaded_pkgs(d):
	global download_folder
	global desc_folder
	global inst_path
	downloaded = os.listdir(download_folder)
	if len(downloaded) == 0:
		d.infobox("Download folder is empty")
		return
	if len(downloaded) > 0:
		heading = "Choose package(s) to Install"
		maxLen = len(heading)
		downloaded_list = []
		for dl in downloaded:
			if len(dl) > maxLen: maxLen = len(dl)
			downloaded_list.append((dl,"",0))
		inst_choice = d.checklist(heading,downloaded_list,maxLen+12,len(downloaded)+6,len(downloaded))
		if len(inst_choice) > 0:
			msg = "Installing packages requires root access.\n"
			msg += "Please enter your password."
			while 1:
				pw = d.passwordbox(msg,40,10,1)
				if pw != "": break
			for pkg in inst_choice:
				descFile = desc_folder + "/" + pkg.replace(".tgz",".txt")
				been_inst_path = "/var/log/packages/" + pkg.replace(".tgz","")
				d.infobox(descFile,100,20)
				inst_cmd += "su -c 'upgradepkg --install-new " + download_folder + "/" + pkg + "'"
				# need commands here to send inst_cmd + pw
				# want to run in background
				
				while 1:
					if os.path.exists(been_inst_path): break
					time.sleep(0.5)
	inst_pkglist = get_installed_pkgs(d)
	os.unlink(inst_path)
	output = open(inst_path,'w')
	for pkg in inst_pkglist:
		output.write(str(pkg) + "\n")
	output.close()
	return

APB_4 · 02-27-2005, 07:57 AM

Just got to say thanks to johnMG for the import commands bit. It was just what I needed to make my small MD5 checking script My program