如何从ruby文件中运行命令行命令？

Question

I have a gem installed that displays a ascii image of a train moving across the terminal screen when someone types "ls". I also have a file called runner.rb.

If it's possible, how can I input the "ls" command to the terminal from within the ruby file?

Answer 1

cmd = "ls > somefile.txt"
system( cmd )

or even just simply

system( "ls" )

Thus, you can use system.

Answer 2

You can also use ( ` ) character to execute Linux commands from ruby file.

eg

`ls` ## OR `whoami` etc.

Answer 3

If you want to execute the command as if you were sitting in the shell (so its output displays, etc.), use system .

> system('ls')
Look        At        All
My          Cool      Files
=> true

If you want to capture the output for use, use backticks.

> files = `ls`
=> "Look\nAt\nAll\nMy\nCool\nFiles\n"

You can interpolate in backticks if you want to (and obviously in the string you pass to system ).