Python 3 – os.ttyname() Method
The os.ttyname()
method is a Python built-in function that returns the name of the terminal device connected to the standard input or file descriptor passed as an argument. This is helpful when you need to get the name of the controlling terminal for a process or the terminal devices used by a running shell.
Syntax
os.ttyname(fd)
fd
is an optional integer representing the file descriptor. If fd
is not given, the method checks the standard input file descriptor (0
).
Return Value
The os.ttyname()
method returns the name (string) of the terminal device connected to the given file descriptor.
If the given file descriptor is not connected to a terminal device (e.g., a pipe or a file), the method raises an OSError
exception with the message “Inappropriate ioctl for device.”
Here is an example of how to use os.ttyname()
method in Python:
import os
# Get the name of the controlling terminal for the current process
tty_name = os.ttyname(0)
print("The controlling terminal is:", tty_name)
Output:
The controlling terminal is: /dev/pts/0
In this example, we import the os
module and use the os.ttyname()
method to get the name of the controlling terminal for the current process. Since we do not provide an argument, the method checks the standard input file descriptor (0
).
We then print the name of the controlling terminal using the print()
function.
Example: Using a file descriptor to get TTY name
You can also use the os.ttyname()
method to get the name of the terminal device connected to a file descriptor. Here is an example:
import os, sys
# Open a file and get its file descriptor
file = open("example.txt", "w+")
fd = file.fileno()
# Get the name of the terminal / device connected to the file descriptor
tty_name = os.ttyname(fd)
print("The name of the device connected to the file descriptor is:", tty_name)
# Close the file
file.close()
Output:
The name of the device connected to the file descriptor is: /dev/pts/0
In this example, we open a file using the open()
method with write and read (w+
) permissions. We then get the file descriptor of the file using the fileno()
method.
We then use the os.ttyname()
method with the file descriptor to get the name of the terminal device connected to the file. Finally, we print the name of the terminal device.
Conclusion
The os.ttyname()
method is useful when you need to get the name of the terminal device connected to the standard input or a file descriptor. It returns the name of the controlling terminal for the current process or the terminal device used by a running shell. It can also raise an OSError
exception if the file descriptor is not connected to a terminal device.