io.md

IO Streams

• There are always three default streams: stdin, stdout and stderr
• Each stream has its own file descriptor
  • stdin = standard input = 0
  • stdout = standard output = 1
  • stderr = standard error = 2
• Processes inherit them from their parents by default. Redirection can be done.

filename

#### Demo

python3 ./examples/io/example.py

cat ./examples/io/example_input

python3 ./examples/io/example.py 1>/tmp/io_redirection_stdout 2>/tmp/io_redirection_stderr 0<./examples/io/example_input

python3 ./examples/io/example_with_sleep.py 1>/tmp/io_redirection_stdout 2>/tmp/io_redirection_stderr 0<./examples/io/example_input

Open another shell

ps aux |grep example_with_sleep

lsof -p <pid>

### References