eksek

eksek is a library to run shell commands synchronously and obtain any of the standard output, standard error, and exit code with flexibility.

Features

Basic usage

Use the eksek method to execute a command:

eksek 'echo Hello'

or the kapture method to execute a command but "capture" the standard output and standard error in a fashion similar to Kernel#\`` (backticks) or %x()`.

kapture 'echo Hello'

These methods return an EksekResult object providing the following methods:

• exit returns the exit code.
• stdout returns the standard output as a string if kapture was called.
• stderr returns the standard error as a string if kapture was called.
• success? returns true or false depending of the exit code (0 for true).
• success! throws an exception if the command exited with a non-0 code.

The success! method can be chained with any other of the above ones and it is wrapped in the convenience method eksek! to have a "fail or return" like so:

puts eksek!('echo Hello').stdout # Hello

# The above is essentially the same as:

puts eksek('echo Hello').success!.stdout

Passing other options

eksek has the same signature as Process#spawn. This means that:

• the first parameter can optionally be a hash, passed as the process environment;
• the command can be passed as a single string or as variable-length arguments;
• other options can be passed as hash arguments.

Additionally, the environment will have its keys stringified, so that symbols can be used too. For example:

r = eksek { A: 'Hello' }, 'echo $A'
puts r.stdout # Hello

r = eksek 'echo', 'Hello'
puts r.stdout # Hello

r = eksek 'echo $PWD', chdir: '/tmp'
puts r.stdout # /tmp

Further information

In case you prefer an object oriented method, you can also use the Eksekuter class that is used by the eksek method directly. The following examples are basically the same:

# With eksek
eksek 'echo Hello'
kapture 'echo Hello'

# With Eksekuter
Eksekuter.new.exec('echo Hello')
Eksekuter.new.capture('echo Hello')