Can you tell us what exactly you are having a problem with? AFAIK there is no shortcut for selecting all the points on a curve, but Shift click works OK. With earlier versions of Photoshop you could Ctrl (Cnd) click anywhere on the image to place a point on the curve that matched that position's tonal value. Nowdays we have the scrubby slider which lets you click and drag on the image. Once a point is active, you can also use the cursor keys for fine adjustments.
I'm moving the whole curve up/down. Since we can shift select all the points, one would think that there would be an easy way to move the whole curve to shift the adjustment. I would think this would be a common task, though I didn't think of it until now...
I guess that you are using a Curves adjustment layer:
To move selected points on the curve, press the arrow keys.
If using the modal curves:
Control (Mac) + tab and CTRL+ Tab (Win) will toggle focus from one point on the curve to another (as will the + and – keys).
Shift click to select multiple points on the curve. (I wish one could Shift+Ctrl+Tab)
Pierre, I think he is talking about the fact if you hold down the Shift key, you can select more than one point on the curve. This locks the curve between those points, and lets you move them as a unit, so to speak. It's not something I have ever found a use for though.
Yes, I think that he wants to be able to nudge the entire curve by a few pixels. for that he selects the points by shift+clicking them, then using the arrow keys to nudge them all.
Hence I gave the shortcuts to select next and previous points, as an alternate method of selecting them.
I added that there does not seem to be a keyboard shortcut to add other selected points to an already selected one.
I never found a use for it either, but recently I opened a file with a curves adjustment layer and I wanted to darken the whole thing a bit. The curve can take awhile to 'get right' as I'm sure you know. At that point I discovered that I could shift-click to add points on the curve to a selection and it occured to me that this should be a basic feature. I could find a way to do it, hence my question.
Thanks for the replies.