Usefull Shell Commands

Pack folder and backup database

Backup folder. Run as sudo, other users will change the original permissions

tar -zcf wp03.tar.gz wp03/

Backup database

mysqldump -u root -p -C albert > albert.sql.tgz

Create user with home folder, shell & password

sudo useradd -m -d /home/mike -s /bin/bash -c "Mike" -U mike
sudo passwd mike
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully

Numeric permissions in console

$ ls -la | 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}'
775 drwxrwxr-x  9 3173 3173   4096 Oct 12 20:01 .
755 drwxr-xr-x  4 3173 3173   4096 Oct 12 21:54 ..
755 drwxr-xr-x  6 3173 3173   4096 Oct 12 19:08 app
755 drwxr-xr-x  2 3173 3173   4096 Oct  9 15:46 bin
644 -rw-r--r--  1 3173 3173   2111 Mar 11  2017 composer.json
664 -rw-rw-r--  1 3173 3173 102342 Oct 12 19:08 composer.lock

Search file names and file content

find file that begins with example case insensitive search

find . -iname "example*" -print

finds string `getcol` in js files in current folder and it`s subfolders, print file name, line number and the line

find . -type f -name "*.js" -exec grep -in --with-filename getcol {} \;

Set permissions for files and folders

sudo find /var/www -type d -exec chmod 775 {} \;  # rwxrwxr-x
sudo find /var/www -type f -exec chmod 664 {} \;  # rw-rw-r--