linux chmod code example
Example 1: bash how do permissions work
# How permissions/changing permissions works in linux. Permissions are
# generally listed in a format like rwxrw-r--, where r, w, x, and -
# stand for read, write, execute, and no permission respectively. There
# are basically three groups of rwx permissions: user, group, others
# and depending on your relationship to the files, you might be any one
# of these.
# To change file permissions, (e.g. chmod ### file), you need to
# indicate three decimal digits (0-7) which specify the three sets
# of permissionswhen converted to binary. Briefly, a decimal number
# between 0 and 7 can be represented by a three digit binary string.
# The binary string sets the permissions by treating 1 as "true" or
# permission granted and 0 as "false", or permission denied. See the
# table below for all the conversions and their meanings:
Decimal Binary Permission Permission meaning
7 111 rwx read, write, and execute
6 110 rw- read and write
5 101 r-x read and execute
4 100 r-- read only
3 011 -wx write and execute
2 010 -w- write only
1 001 --x execute only
0 000 --- none
Example 2: chmod
sudo chmod -R 777 name-file-wht-upu-want
sudo chmod 644 #for example file /etc/hosts
https://ss64.com/bash/chmod.html
Example 3: chmod usage
The three rightmost digits define permissions for the:
file user, the group, and others.
Example usage: sudo chmod 777 testfile.txt
# Permission rwx Binary
7 read, write and execute rwx 111
6 read and write rw- 110
5 read and execute r-x 101
4 read only r-- 100
3 write and execute -wx 011
2 write only -w- 010
1 execute only --x 001
0 none --- 000
Example 4: chmod
chmod u=rwx,g=rx,o=r myfile
chmod 754 myfile
# 4 stands for "read",
# 2 stands for "write",
# 1 stands for "execute", and
# 0 stands for "no permission."
Example 5: change mode in linux
For changing permissions mode of files as "file.exe" follow next examples idea:
chmod file.exe ugo+x #Add x:execute permissions to u:user g:gropu and o:others
chmod file.exe o-rw #Remove r:read and w:write permissions to o:others
chmod file.exe +rwx #Add all r:read, w:wirte and x:execute permissions to all.
Example 6: chmod
chmod file.exe +rwx
chmod -R 777 ./