Mac OS X v10.5, 10.6: How to capture a packet trace
In this advanced article, learn how to capture a packet trace; for example, you may be asked to do this when troubleshooting a network connectivity issue. These steps use Terminal and the the tcpdump command; if you are not familiar with using the Terminal, you may want to use for third-party software that can perform a packet trace instead.
SCREENCAPTURE(1) BSD General Commands Manual SCREENCAPTURE(1)NAME
screencapture -- capture images from the screen and save them to a file or the clipboard
SYNOPSIS
screencapture [-SWCTMPcimswxto] file
DESCRIPTION
The screencapture utility is not very well documented to date. A list of options follows.
-c Force screen capture to go to the clipboard.
-C Capture the cursor as well as the screen. Only allowed in non-interactive modes.
-i Capture screen interactively, by selection or window. The control key will cause the screen shot to go to the clipboard. The space
key will toggle between mouse selection and window selection modes. The escape key will cancel the interactive screen shot.
-m Only capture the main monitor, undefined if -i is set.
-M Open the taken picture in a new Mail message.
-o In window capture mode, do not capture the shadow of the window.
-P Open the taken picture in a Preview window.
-s Only allow mouse selection mode.
-S In window capture mode, capture the screen instead of the window.
-t <format> Image format to create, default is png (other options include pdf, jpg, tiff and other formats).
-T <seconds> Take the picture after a delay of <seconds>, default is 5.
-w Only allow window selection mode.
-W Start interaction in window selection mode.
-x Do not play sounds.
-a Do not capture attached windows.
-r Do not add screen dpi meta data to captured file.
files where to save the screen capture, 1 file per screen
BUGS
Better documentation is needed for this utility.
SECURITY CONSIDERATIONS
To capture screen content while logged in via ssh, you must launch screencapture in the same mach bootstrap hierarchy as loginwindow:
PID=pid of loginwindow
sudo launchctl bsexec $PID screencapture [options]
HISTORY
A screencapture utility first appeared in Mac OS X v10.2.
Mac OS June 16, 2004 Mac OS
