Programming Cheatsheets

js-cheatsheets.js

// element dimension
var w = $(this).width();
var h = $(this).height();

// current window(viewport) dimension
var w = $(window).width();
var h = $(window).height();

// document dimension
var w = $(document).width();
var h = $(document).height();

// enclosure a scope
(function(params) {
  // real code
})(params);

python-cheatsheets.py

# check if file exists
os.path.isfile(filename)

# command line parameters parsing
parser = argparse.ArgumentParser()
parser.add_argumoent("-c", "--config", metavar="filename", dest="config_file", help="specify a local config file")
args = parser.parse_args()

config_file = args.config_file

# check root
os.geteuid() == 0

# check python version
sys.version_info < (2, 7)

# exit python script
sys.exit(errmsg)         # return 1 to shell

# uppercase/lowercase
str.lower()
str.upper()

# strip whitespace
str.strip()

# copy file
shutil.copyfile(src, dst)

# remove tree
shutil.rmtree('folder_name')

# make directory
os.makedirs(path)

# copy tree
shutil.copytree(src, dst)

# get current datetime as string
from datetime import datetime
datetime.now().strftime("%Y%m%d%H%M%S")

# run shell command and catch stdout/stderr
p = subprocess.Popen(['/bin/ls', '-l'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdout, stderr = p.communicate()
if p.returncode == 0:
  # success
else:
  # fail

# get gid/uid
try:
  uid = pwd.getpwnam('apache').pw_uid
  gid = grp.getgrnam('apache').gr_gid
except KeyError:
  log.error("apache does not exist")

shell-cheatsheet.sh

# get git commit count
$ git shortlog -s -n | awk 'BEGIN { count = 0; } { count += $1; } END { print count; }'

# git svn revision
$ svn info | grep "Revision:" | awk '{ print $2; }'