screeninfo

Updated: April 19, 2023

Decode contents of binary files in /dev/screen for debugging

Syntax:

screeninfo [-blits  | -event | -input | -requests]
           [-w]
           [-q]
           filename

Runs on:

QNX Neutrino

Options:

-blits
Decode a blit log to provide information such as the following:
  • position of the rectangle in the source buffer
  • position of the rectangle in the destination buffer
The buffer size can be configured in the graphics.conf file. For more information about the buffer size, see the blits-logsize in the Configure globals subsection.
-event
Decode an event queue log to provide information such as the following:
  • event type
  • event timestamp
  • event data
-input
Decode an input log to provide information such as the following:
  • input device type
  • input device data

You can set the log size in the graphics.conf file. For more information, see Configure globals subsection.

-requests
Decode a requests log to provide information such as the following:
  • context ID
  • message type
  • message subtype
  • log size

You can set the log size in the graphics.conf file. For more information, see Configure globals subsection.

-w
wait for more events to arrive; use Ctrl-C to exit.
-q
Show only requests with errors.

Description:

The screeninfo utility is a command-line tool for displaying the contents of binary files generated in /dev/screen on the target. For example, you might want to take a copy of the binary file before a crash occurs (if known) or at a critical debug point, such as when a user injected an event.

For more information, see the Debugging section in this guide.

The following log types can be specified using the corresponding option. If you don't specify any log type, then this command uses the name of the specified filename to determine how to decode it. However, if you rename the file, then you must specify the log type; otherwise, screeninfo won't know how to decode the specified log file.

Log type Log file
blits

/dev/screen/0/blt-1

/dev/screen/0/blt-2
event

/dev/screen/application_pid/ctx-context_id

where application_pid is the process ID of the running Screen application, and context_id is the ID of the application's Screen context. To see the events, the application must be running.
Note: In addition to the ctx-* file, in the /dev/screen/application_pid/ directory, there are other text-based files that you view without using screeninfo, which are as follows:
  • dev-dev-id
  • dpy-dpy-id
  • grp-grp-id
  • pix-pix-id (a directory that has str-pix-id files that you view)
  • ssn-ssn-id
  • str-str-id (a directory that has str-str-id files that you view)
  • win-win-id
input

/dev/screen/input
requests

/dev/screen/requests

Examples:

View blit and request logs (without specifying the log type options): 
screeninfo /dev/screen/0/blt-1
screeninfo /dev/screen/requests
View blit logs: 
screeninfo -blits /dev/screen/0/blt-2
View context information and event logs: 
screeninfo -events /dev/screen/1597661/ctx-0
View input logs in continuous mode: 
screeninfo -w /dev/screen/input
View requests with errors: 
screeninfo -q /dev/screen/requests