From f4a3e0bceb57466c31757f25e4e0ed108d1299ec Mon Sep 17 00:00:00 2001 From: "Dr. Werner Fink" Date: Wed, 22 Sep 2010 12:45:40 +0200 Subject: tty: Add a new file /proc/tty/consoles Add a new file /proc/tty/consoles to be able to determine the registered system console lines. If the reading process holds /dev/console open at the regular standard input stream the active device will be marked by an asterisk. Show possible operations and also decode the used flags of the listed console lines. Signed-off-by: Werner Fink Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- Documentation/filesystems/proc.txt | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a6aca874088..98223a67694 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1075,6 +1075,7 @@ Table 1-11: Files in /proc/tty drivers list of drivers and their usage ldiscs registered line disciplines driver/serial usage statistic and status of single tty lines + consoles registered system console lines .............................................................................. To see which tty's are currently in use, you can simply look into the file @@ -1093,6 +1094,37 @@ To see which tty's are currently in use, you can simply look into the file /dev/tty /dev/tty 5 0 system:/dev/tty unknown /dev/tty 4 1-63 console +To see which character device lines are currently used for the system console +/dev/console, you may simply look into the file /proc/tty/consoles: + + > cat /proc/tty/consoles + tty0 -WU (ECp) 4:7 + ttyS0 -W- (Ep) 4:64 + +The columns are: + + device name of the device + operations R = can do read operations + W = can do write operations + U = can do unblank + flags E = it is enabled + C = it is prefered console + B = it is primary boot console + p = it is used for printk buffer + b = it is not a TTY but a Braille device + a = it is safe to use when cpu is offline + * = it is standard input of the reading process + major:minor major and minor number of the device separated by a colon + +If the reading process holds /dev/console open at the regular standard input +stream the active device will be marked by an asterisk: + + > cat /proc/tty/consoles < /dev/console + tty0 -WU (ECp*) 4:7 + ttyS0 -W- (Ep) 4:64 + > tty + /dev/pts/3 + 1.8 Miscellaneous kernel statistics in /proc/stat ------------------------------------------------- -- cgit v1.2.3-70-g09d2