I'm trying to do the following..
if "ps | grep -e file" then
true;
else
false;
What would I need to do to make the string n the if statement execute the linux command listed?
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4 Answers
Simply use system("command"). It'll return true if the command was successfully executed.
EDIT Just read your question again, and I believe that what you're looking for is this:
if `ps | grep -e file`.empty? # no matches
true
else
false
end
1 Comment
igorw
Was about to add that empty? call, please add an end statement.
Don't have to call grep. Just call ps and let Ruby find the things you want.
if `ps`["file"]
...
else
...
end
Comments
Linux ps has a -C switch to check for a specific program name:
if "ps -C file" then
true;
else
false;
however - if you have a construct like
if (predicate) then true; else false;
it should be the same as
(predicate)
Comments
You can run your Linux Command like this
`echo "done"`
This will print done as output.
