following one of the comment: @astro Yes. An XSI compliant echo actually supports no options at all. See here for how echo is supposed to work: POSIX. 2008

following one of the comment: @astro Yes. An XSI compliant echo actually supports no options at all. See here for how echo is supposed to work: POSIX. 2008 §echo the link goes to http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ec... ; here I read OPERANDS The following operands shall be supported: string A string to be written to standard output. [...] The following character sequences shall be recognized on XSI-conformant systems within any of the arguments: [...] \c Suppress the <newline> that otherwise follows the final argument in the output. All characters following the '\c' in the arguments shall be ignored. wait, what???