Old code

exec_cmd('ping {ip}'.format(ip=ip))

Rewritten code

exec_cmd(format_cmd('ping {ip}', ip=ip))

Examples

format_cmd('ping {ip}', ip="$(rm -rf /)")
  $ ping '$(rm -rf /)'
  ping: cannot resolve $(rm -rf /): Unknown host

format_cmd('ping {ip}', ip='$(rm -rf '/')')
  $ ping '$(rm -rf '"'"'/'"'"')'
  ping: cannot resolve $(rm -rf '/'): Unknown host

Old code

exec_cmd("python -c'print(\"{arg}\")'".format(arg=arg))

Rewritten code

exec_cmd(format_cmd("python -c'import sys; print(sys.argv[1])' {arg}", arg=arg))

Examples

format_cmd("python -c'import sys; print(sys.argv[1])' {arg}", arg="'$(rm -rf /)'")
  $ python -c'import sys; print(sys.argv[1])' ''"'"'$(rm -rf /)'"'"''
  '$(rm -rf /)'