The simple command below does not work on CentOS 7:
ifconfig | convert label:@- cmd.png
convert: not authorized `@-' @ error/constitute.c/ReadImage/454.
convert: no images defined `cmd.png' @ error/convert.c/ConvertImageCommand/3046.
I do not known any other command or workaround to do this

Any ideas ?
Version used:
convert -version
Version: ImageMagick 6.7.8-9 2016-06-16 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP
Thanks in advance.