Sometimes you need to get numerical permissions while doing ls. Numerical permissions are like 777 or 644.
Here is how to do it:
# ls -l | awk '{k=0;for(i=0;i<=8;i++)k+=((substr($1,i+2,1)~/[rwx]/) *2^(8-i));if(k)printf("%0o ",k);print}'
You can create a bash file in /usr/local/bin to access this command quickly