{"id":1946,"date":"2020-01-14T18:02:41","date_gmt":"2020-01-14T10:02:41","guid":{"rendered":"https:\/\/www.techcoil.com\/blog\/?p=1946"},"modified":"2020-05-12T14:12:47","modified_gmt":"2020-05-12T06:12:47","slug":"how-to-terminate-screen-terminal-sessions-cleanly-on-macos","status":"publish","type":"post","link":"https:\/\/www.techcoil.com\/blog\/how-to-terminate-screen-terminal-sessions-cleanly-on-macos\/","title":{"rendered":"How to terminate screen terminal sessions cleanly on macOS"},"content":{"rendered":"

So how do you communicate with a serial device that is connected to your Mac?<\/p>\n

In this situation, you can use the screen command on your Mac to do so.<\/p>\n

After you terminate the serial session with Ctrl+A+D, you may find that the serial device is still being hogged by the screen command.<\/p>\n

When you try to access the device again, you may encounter a Resource busy<\/strong> error message. <\/p>\n

For example, after I detached my screen terminal from \/dev\/cu.SLAB_USBtoUART<\/strong>, I will get the following message if I try to connect to the same device again:
\n
\nCannot open line '\/dev\/cu.SLAB_USBtoUART' for R\/W: Resource busy
\n<\/strong><\/p>\n

Given these points, this post shows how we can terminate screen terminal sessions cleanly on macOS.<\/p>\n

Steps to terminate screen terminal sessions cleanly on macOS<\/h2>\n

In order to create the situation of resource hogging, let's connect your serial device with the screen command. For example, I may connect to my ESPx device with the following command:<\/p>\n

\r\nscreen -port \/dev\/cu.SLAB_USBtoUART 115200\r\n<\/pre>\n
After doing so, detach the session by pressing Ctrl+A+D<\/strong>.<\/p>\n
When you do so, the serial device is still being locked by the screen command. <\/p>\n
Given that, let's list the screens that are being locked with the following command:<\/p>\n
\r\nscreen -list\r\n<\/pre>\n
After the command completes, you should see something like this the following as an output:<\/p>\n
\r\nThere is a screen on:\r\n\t10184.ttys001.ZZZM56582454A\t(Detached)\r\n1 Socket in \/var\/folders\/vs\/lx78cw0x7m921p6qdmw9h4xm0000gr\/T\/.screen.\r\n<\/pre>\n
In order to terminate the screen terminal cleanly, run the following command:<\/p>\n
\r\nscreen -X -S 10184 quit\r\n<\/pre>\n
After the command completes, you can run the screen command to verify if the session had been terminated:<\/p>\n
\r\nscreen -list\r\n<\/pre>\n
When the previous terminal session had been terminated successfully, you should see the following output:<\/p>\n
\r\nNo Sockets found in \/var\/folders\/vs\/lx78cw0x7m921p6qdmw9h4xm0000gr\/T\/.screen.\r\n<\/pre>\n\n