检查命令是否打印出与Ruby的正则表达式匹配的字符串？

Question

I want to run:

> ruby --version
ruby 1.9.2p0 (2010-08-18 revision 29034) [x86_64-darwin10.4.0]

and then see if 1.9.2 is printed out. If so, i return true .

How would this method look like using a regexp?

Answer 1

我建议使用“ RUBY_VERSION”，但是您可以执行以下操作：

`ruby --version`.include? "1.9.2"

Answer 2

RUBY_VERSION == "1.9.2"

Answer 3

Maybe I am off the track here but you do seem to want to check the version from the shell ? Something like this then will do it.

export VERSION=`ruby --version | grep 1.9.2`
if [[ -n "$VERSION" ]] ; then
  echo "you have the right version yay!"
else
  echo "bummer dude ><!"
fi

Answer 4

The regex for this is simply

/1.9.2/

So

s=`ruby --version`
return true if s=~/1\.9\.2/

(updated)