2.1 KiB
https://wiki.bash-hackers.org/
Update PostgreSQL
wget -q https://www.postgresql.org/media/keys/ACCC4CF8.asc -O - | sudo apt-key add -
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ lsb_release -cs-pgdg main" >> /etc/apt/sources.list.d/pgdg.list'
sudo apt-get update
sudo apt-get install postgres-10
sudo su - postgres
psql
Set PSQL defaults
put .psqlrc in home directory \set x '\setenv PAGER less' \set xx '\setenv PAGER 'pspg -bX --no-mouse''
Size of directory: du -hcs //mnt/c/PostgreSQL/cassandra30/
list lines in file wc file
General tasks
wc - print line counts
free - memory usage
du - disk space by file
Resource Limit
ulimit -a to see all limits
file at /etc/security/limits.conf to configure defaults
MySQL
connection like mysql -u root -p
show databases;
user is in the format root@127.0.0.1
grant all prviileges on *.* to 'root'@'127.0.0.1'
data is stored in /var/lib/mysql
failure to drop a db can be due to presence of unknown file in the database directory
SSH
add client
- client uses ssh-keygen to create a key in
/home/un/.ssh/under filesid_rsaandid_rsa.pub - host setup //etc/ssh/sshd_config to allow passwords and restart
- client uses
ssh-copy-id host_address -p port_numto move the key to the host - client uses
sshto login
rename files in the current director
rename 's/find_this_in_the_file_name/replace_with_this/g' *