File Permissions

chmod:

sudo chmod <who to assign><permissions> <file/folder names>
sudo chmod u+x ./file.txt  # assigns the user execute permissions
sudo chmod +x ./file.txt  # assigns all users execute permissions
	sudo chmod a+x ./file.txt  # equivalent
sudo chmod g-x ./file.txt  # removes execute permissions for the group
# 'who' codes
o  # owner
g  # group
u  # user
a  # all users
# Binary permission codes. Add together to assign.
r = 4 = 100b
w = 2 = 010b
x = 1 = 001b

decimal code
	o	o	o		g	g	g		u	u	u
	r	w	x		r	w	x		r	w	x
700	1	1	1		0	0	0		0	0	0
600	1	1	0		0	0	0		0	0	0
500	1	0	1		0	0	0		0	0	0
400	1	0	0		0	0	0		0	0	0
300	0	1	1		0	0	0		0	0	0
200	0	1	0		0	0	0		0	0	0
100	0	0	1		0	0	0		0	0	0
000	0	0	0		0	0	0		0	0	0

binary code	decimal code	owner	group	user (all others)
ooo ggg uuu
rwx rwx rwx
100 000 000	400	r--	---	---
010 000 000	200	-w-	---	---
001 000 000	100	--x	---	---
000 100 000	040	---	r--	---
000 010 000	020	---	-w-	---
000 001 000	010	---	--x	---
111 000 000	700	rwx	---	---
110 000 000	600	rw-	---	---
101 000 000	500	r-x	---	---
011 000 000	300	-wx	---	---
111 000 100	704	rwx	---	rw-