Python: Operating System Services

In this blog we will cover some operating system interfaces that python provide.

First when we talk about operating system we mean the management of computer hardware and software resources and providing common services for computer programs.

Python has the power to easily manipulate the system calls, Operating environment, Processes, Timers, Signal handling, Error reporting etc…

Let’s start by the Environment Variables:

user = os.environ[’USER’]

os.environ[’PATH’] = "/bin:/usr/bin"

Working directory

os.chdir(path) # Change current working directory
os.getcwd() # Get it

Users and groups

os.getegid() # Get effective group id
os.geteuid() # Get effective user id
os.getgid() # Get group id
os.getuid() # Get user id
os.setgid(gid) # Set group id
os.setuid(uid) # Set user id

Process

os.fork() # Create a child process
os.execv(path,args) # Execute a process os.execve(path, args, env)
os.execvp(path, args) # Execute process, use default path os.execvpe(path,args, env)
os.wait([pid)] # Wait for child process
os.waitpid(pid,options) # Wait for change in state of child
os.system(command) # Execute a system command
os._exit(n) # Exit immediately with status n