mkdir function mkfifo function open function - pathsep character pipe function file descriptors and functionality redirecting output popen function communicating with exit status functionality launching mail program redirecting streams shell listing command - standard streams and portability constants program exits putenv function read function remove function rename function sep character shell commands from scripts - spawnv function - spawnve function - startfile function stat function system function tools by functional area unlink function walk function find function and functionality handling unicode filenames scanning directory trees - write function os path module abspath function functionality isdir function isfile function join function samefile function split function tools supported - output class output files - index output stream buffering deadlocks and flushes - pexpect and program exits and pty module and pack class packer geometry manager combining with grid - defined expand and fill options grid comparison - layout system making expandable resizing widgets packing scroll bars widgets without saving - paging script example panedwindow widget class parallel processing defined forking processes - ipc support - multiprocessing module - portable framework program exits - socket server portability and - spawning clients - starting programs - system tools coverage threads - parameters passing in hidden fields passing in hidden form fields passing in urls - - - query parent process parsing binary data - command-line arguments custom language parsers adding parse tree interpreter expression grammar parse tree structure parser code -