Another possible option that comes to my mind is to shell out to the bc Unix or Linux utility. bc can be used in non-interactive mode in various ways, including piping (echo "42/7" | bc), shell redirections, and Un*x heredocs.

How to make things even worse. I smell shell injection: "Dear script, please evaluate 1 + $(rm -rf /) or 1 + ";rm -rf /;echo " for me." (echo "1 + $(rm -rf /)" | bc resp. echo "1 + ";rm -rf /;echo "" | bc) Shelling out ain't that easy if you want to do it right: The problem of "the" default shell

And even if you shell out safely, the program you feed the input into may have security issues. See Morris_worm for a really old example, or CVE-2012-1165 for a younger one.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

In reply to Re^2: Extending a perl program with Scheme, Lua, or JS by afoken
in thread Extending a perl program with Scheme, Lua, or JS by bcrowell2

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