忽然發現截圖不好使了！！ ctrl-shift-cmd-3/4，都沒效果！ 嘗試了改defaults read com.apple.screencapture 居然什麼都沒有- -！ 問題還沒解決，先記下！
不過塞翁失馬焉知非福阿，HOHO，發現了個更方便的小東西！
其實截圖是有cli的，/usr/sbin/screencapture，可以man screencapture 看具體引數，截圖最常用的其實就是：
- screencapture /my/path 截全屏，另存為檔案/my/path！
- screencapture -i /my/path 自定義選取
- screencapture -w /my/path 視窗選擇模式
若想存入剪下板而不是檔案，搭配引數c即可，如
- screencapture -c
- screencapture -ci
- screencapture -cw
使用方法詳情：
usage: screencapture [-icMPmwsWxSCUto] [files]
-c force screen capture to go to the clipboard
-C capture the cursor as well as the screen. only in non-interactive modes
-d display errors to the user graphically
-i capture screen interactively, by selection or window
control key - causes screen shot to go to clipboard
space key - toggle between mouse selection and
window selection modes
escape key - cancels interactive screen shot
-m only capture the main monitor, undefined if -i is set
-M screen capture output will go to a new Mail message
-o in window capture mode, do not capture the shadow of the window
-P screen capture output will open in Preview
-s only allow mouse selection mode
-S in window capture mode, capture the screen not 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
files where to save the screen capture, 1 file per screen