Overview

Ruby’s system method can be used to run system commands in Ruby. Below is the syntax for the same

system(some_command)

Some important points to note about system command

• It will wait until the command is executed

• It will return true if the command is a success

• It will return false if the command is a failure and returns an error code

• It will return nil if the command is not found

Let’s check out a program for the same

Program

output = system("pwd")
puts "For pwd command: " + output.to_s

output = system("exit 1")
puts "For exit 1 command: " + output.to_s

output = system("pwd1")
puts "For pwd1 command: " + output.to_s

Output

<current_directory>
For pwd command: true
For exit 1 command: false
For pwd1 command:

In the above program, there are three cases

• When the command is a success

output = system("pwd")
puts "For pwd command: " + output.to_s

The output, in this case, is true

<current_directory>
For pwd command: true

• When the command is a failure

output = system("exit 1")
puts "For exit 1 command: " + output.to_s

The output, in this case, is false

For exit 1 command: false

• When the command doesn’t exist i.e pwd1 is an invalid command

output = system("pwd1")
puts "For pwd1 command: " + output.to_s

The output, in this case, is  nil

For pwd1 command: