aboutsummaryrefslogtreecommitdiffstats
path: root/lib/alaveteli_external_command.rb
blob: 79711328c0b765df22fa43afb19bbc02de1d36f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
require 'external_command'

module AlaveteliExternalCommand
    class << self
        # Final argument can be a hash of options.
        # Valid options are:
        # :append_to - string to append the output of the process to
        # :stdin_string - stdin string to pass to the process
        # :binary_output - boolean flag for treating the output as binary or text (only significant
        #                  ruby 1.9 and above)
        # :memory_limit - maximum amount of memory (in bytes) available to the process
        def run(program_name, *args)
            # Run an external program, and return its output.
            # Standard error is suppressed unless the program
            # fails (i.e. returns a non-zero exit status).
            opts = {}
            if !args.empty? && args[-1].is_a?(Hash)
                opts = args.pop
            end

            program_path = find_program(program_name)

            xc = ExternalCommand.new(program_path, *args)
            if opts.has_key? :append_to
                xc.out = opts[:append_to]
            end
            if opts.has_key? :binary_output
                xc.binary_mode = opts[:binary_output]
            end
            if opts.has_key? :memory_limit
                xc.memory_limit = opts[:memory_limit]
            end
            xc.run(opts[:stdin_string] || "", opts[:env] || {})

            if !xc.exited
                # Crash or timeout
                $stderr.puts("#{program_name} #{args.join(' ')}:exited abnormally")
                return nil
            elsif xc.status != 0
                # Error
                $stderr.puts("Error from #{program_name} #{args.join(' ')}:")
                $stderr.print(xc.err)
                return nil
            else
                if opts.has_key? :append_to
                    opts[:append_to] << "\n\n"
                else
                    return xc.out
                end
            end
        end

        def find_program(program_name)
            if program_name =~ %r(^/)
                return program_name
            else
                search_path = AlaveteliConfiguration::utility_search_path
                search_path.each do |d|
                    program_path = File.join(d, program_name)
                    return program_name if File.file? program_path and File.executable? program_path
                end
                raise "Could not find #{program_name} in any of #{search_path.join(', ')}"
            end
        end
    end
end