Section 14.8. Miscellaneous Operating System Interface

14.8. Miscellaneous Operating System Interface

In this chapter, we have seen various ways to interact with your operating system (OS) via the os module. Most of the functions we looked at dealt with either files or external process execution. There are a few more that allow for more specific actions for the current user and process, and we will look at them briefly here. Most of the functions described in Table 14.8 work on POSIX systems only, unless also denoted for Windows environment.

Table 14.8. Various os Module Attributes ( Also available for Win32)

os Module Attribute	Description
uname()	Obtains system information (hostname, operating system version, patch level, system architecture, etc.)
getuid()/setuid(uid)	Gets/sets the real user ID of the current process
getpid()/getppid()	Gets real process ID (PID) of current/parent process
getgid()/setgid(gid)	Gets/sets real group ID (GID) of current process
getsid()/setsid()	Gets session ID (SID) or create and return a new one
umask(mask)	Sets the current numeric umask while returning the previous one (mask is used for file permissions)
getenv(ev)/putenv(ev, value), environ	Gets/sets value of environment variable ev; the attribute os.environ is a dictionary representing all current environment variables
geteuid()/setegid()	Gets/sets effective user ID (UID) of current process
getegid()/setegid()	Gets/sets effective group ID (GID) of current process
getpgid(pid)/setpgid(pid, pgrp)	Gets/sets process GID process pid; for get, if pid is 0, the process GID of the current process is returned
getlogin()	Returns login of user running current process
times()	Returns tuple of various process times
strerror(code)	Returns error message corresponding to error code
getloadavg()[a]	Returns tuple of values representing the system load average during the past 1, 5, and 15 minutes

^[a] New in Python 2.3.