vladpurga

1 Software Design for Flexibility

Новая книга от одного из авторов культовой SICP (Gerald Jay Sussman) и principal author of Scheme (Chris Hanson) - «Software Design for Flexibility. How to Avoid Programming Yourself into a Corner». Авторы задаются «извечным» вопросом о гибкости кода и как ее достичь. Судя по оглавлению речь пойдет о различных техниках и подходах от комбинаторов до DSL и динамического программирования. Звучит очень интересно! https://mitpress.mit.edu/books/software-design-flexibility.

https://t.me/tripovozkiknig/62

2 Domain Modeling Made Functional

Книга про то как делать DDD методами функционального программирования (на F#, но многие аспекты применимы к ЯП без статической типизации)

vladpurga

select last_value from <schema>.<table>_id_seq;

SELECT setval('serial_id_seq',nextval('serial_id_seq')-1);
SELECT currval('serial_id_seq');
SELECT lastval();

vladpurga

ps axf -o ppid,pid,uid,c,stime,tty,time,cmd,stat | grep '[c]ommand'

vladpurga

• http://dfir.pro/index.php?link_id=97048

perl -MRegexp::Debugger -e 'Regexp::Debugger::rxrx("x=x" =~ /.*.*=.*/)

vladpurga

GRANT USAGE ON SCHEMA <name> TO <role>;
GRANT SELECT ON ALL TABLES IN SCHEMA <name> TO <role>;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA <name> TO <role>;

vladpurga

log_line_prefix = '%m (%p:%h:%d:%u:%a:%v:%x) '

2019-08-16 05:08:57.939 GMT (62842:host:database:user:[application]:16/36976788:3643551317) LOG: process 62842 still waiting for ExclusiveLock on tuple (113892,1) of relation 14028231 of database 12345 after 1000.098 ms

%p = 62842
%v = 16/36976788
%x = 3643551317

# special values:

vladpurga

# create directories
mkdir -p /tmp/test_day && cd $_ && mkdir -p today yesterday before_yesterday && cd -

# in linux change modification time
touch -d '-2 days' /tmp/test_day/before_yesterday
touch -d '-1 day' /tmp/test_day/yesterday
touch /tmp/test_day/today

# find directories with modification time older then 24 hours
find /tmp/test_day -mindepth 1 -mtime +0

vladpurga

vimrc-bg-light:
        sed -i 's/^\(set background=dark\)/" \1/' ~/.vimrc; \
        sed -i 's/^\(colorscheme jellybeans\)/" \1/' ~/.vimrc; \
        sed -i 's/^" \(colorscheme solarized\)/\1/' ~/.vimrc; \
        sed -i 's/^" \(set background=light\)/\1/' ~/.vimrc

vladpurga

#!/bin/bash

# add next line into recovery.conf
# recovery_command = '/path/to/recovery_command.sh %f %p'

SOURCE=$1
TARGET=$2
ARCHIVE_DIR=$3
[[ $ARCHIVE_DIR = "" ]] && ARCHIVE_DIR="/path/to/wal/log/archive"

vladpurga

ssh -t host "sudo tune2fs -l /dev/sdb1 | grep -i 'block count' | cut -d':' -f2 | tr -d ' ' | awk 'BEGIN {FS=\"\n\"; RS=\"\"} {print \"/dev/sdb1 space reserved: \"\$2/\$1*100\"%\"}'"