how would i rig a character or the sowrd for unsheathing so the sword doesnt pop out o
It’s less about the rig and more about the animation. There’s not an automatic way to keep one object from clipping outside another during an animation, you’d have to write a custom physics solver into the Blender source code. Instead, you’ll just carefully adjust the animation. One trick that might help- you can use mask modifiers with animated influence to temporarily turn off parts of the sword that are clipping
Welcome 
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for a straigt sword one might “simply” think about a straight unsheating movement so from the moment the hand is gripping the handle and until the swort is unsheating the movements have to be linear.
Of course for a bend/curved sword this has to be in the curvation of the sword.
You may alos have look here:
When you watch a sword being unsheathed in a “real movie,” you might notice that the sequence is done with more than one shot, tightly “cut” for maximum dramatic effect. You could certainly do the same with yours, and simply conceal any “flaws.”
Animate the sheath coming off the sword, make that into an nla strip, parent the sheath to the sword, and set keyframes for the influence of the parenting constraint. Set a keyframe for the influence of the parenting constraint so that it’s at one while the two are connected, then when the sword is drawn, advance a few frames and set it to zero and set another keyframe.