笔记：一些日常cheatsheet

DB
目录

日常cheatsheet～

  • run valgrind for a program
valgrind --tool=memcheck --leak-check=full --log-file=leak.log --soname-synonyms=somalloc=NONE <some_exe> [<some_exe_args>]
  • run tcpdump to capture mysql queries:
tcpdump -r /tmp/a.cap -A -S -n -nn  | grep -i -E "select|insert|update|delete|replace" | sed 's%\(.*\)\([.]\{4\}\)\(.*\)%\3%' | less
  • python scripts:
python -m SimpleHTTPServer 8123
wget -c -r -nH -m --limit-rate=400m "http://ip:8123/xxxx"

python -c 'from zlib import crc32; print crc32("1476777") % 1024'

#!/usr/bin/python
# -*- coding: UTF-8 -*-
import sys
import json
data = ""
for line in sys.stdin:
        data += line
text = json.loads(data)
print(text)
  • tee with a pipe output to screen and a file
echo "hello" | tee abc.txt

  • ps

  • top

  • tasr

  • sar

  • iostat

  • iotop

  • iftop

  • netstat

  • tcpdump

  • Makefile

  • systemtap

py scripts snippet

#!/usr/bin/python3
# -*- coding: utf-8 -*-
...

if __name__ == "__main__":
   ...

vim

set list set nolist noh

  • gcc

  • others

    • system supervisor
    • system crontab settings