CODEWITHSUNDEEP
rubyexec
kaiya
kaiya

Reputation: 312

Getting the ruby exec syntax right

I want to execute a variable shell command through ruby. I am a ruby beginner. I had the command working without variables, but when I tried to set variables the exec command doesn't work and the script stops running. All 3 variables hold Strings.

The print is working fine, but exec not.

print "#{jobserv}" + options[:machines] + " -c touch #{noautooffPath} \n"

exec('"#{jobserv}" + options[:machines] + " -c touch #{noautooffPath}"')

What do i have to do to make the exec right or to get more hints by the system on how to correct this?

jobserv hold a path to an executable file plus options, options[:machines] holds a parameter I give to the last option flag of jobserv.

Upvotes: 0

Views: 374

Answers (1)

matthewd
matthewd

Reputation: 4435

First, check you want exec. Several other options, like system, are more common choices for running a shell command. (Specifically, if exec is successful, the Ruby script will stop executing and be replaced by the command it executes; the rest of the script will never be run.)

You seem to have an extra layer of single quotes in your exec call. You probably want something closer to this:

exec("#{jobserv}" + options[:machines] + " -c touch #{noautooffPath}")

(assuming the print is showing the value you want)

In general, it's safer to avoid the single-string shell form, and pass all the argument individually. That might look more like this:

exec("#{jobserv}#{options[:machines]}", "-c", "touch", noautooffPath)

or:

exec(jobserv, options[:machines], "-c", "touch", noautooffPath)

(depending on whether jobserv and options[:machines] are expected to combine. And it'd look different again if any of those are expected to themselves contain a full multi-argument command invocation.)

Upvotes: 3

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