June 2021 – random linux notes

multiple variable looping bash

If you want to loop through something with more than one variable in bash this is your ticket to ride:

#!/usr/bin/env bash
while read -r x y z; do
echo "$x $y $z"
done <<'_____HERE
a b c
1 2 3
x y z
7 8 9
_____HERE

julia postgres libpq update example

The Julia community seems shy about posting examples of database things…

use LibPQ, Tables

db="db" 
server="localhost" 
usr="psql"
passwd="nope"

conn = LibPQ.Connection("host=$server dbname=$db user=$usr password=$passwd")
sql = """select char from foo""" 

conn2 = LibPQ.Connection("host=$server dbname=$db user=$usr password=$passwd") 
sql2 = prepare(conn2, """update bar set agility = \$1 , bravery = \$2 where char = \$3""" ) 

response = execute(conn, sql) 

for row in rowtable(response)
  ag = agility(row[:char])
  br = bravery(row[:char])
  execute(sql2, (ag, br, row[:char]))
end