This works fine and returns true:

res = system('dir')

This returns false with $? being nil:

res = system('rake')

if I just run rake at the command line it works fine.   I'm sure this
is something simple, but windows is not a development environment I am
used to.

I get

false
rake aborted!
No Rakefile found (looking for: rakefile, Rakefile, rakefile.rb,
Rakefile.rb)
d:/dev/ruby/lib/ruby/gems/1.8/gems/rake-0.6.2/lib/rake.rb:1373:in
`load_rakefile'

on a directory without a rakefile, which is correct :).

system("rake") for the same directory gives a $? of 256.

--------
class ExecCmd
        attr_reader :output,:cmd,:exec_time
        #When a block is given, the command runs before yielding
        def initialize cmd
        @cmd=cmd
        @cmd_run=cmd+" 2>&1" unless cmd=~/2>&1/
        if block_given?
                run
                yield self
        end
        end
        #Runs the command
        def run
                t1=Time.now
                IO.popen(@cmd_run){|f|
                @output=f.read
                @process=Process.waitpid2(f.pid)[1]
                }
                @exec_time=Time.now-t1
        end
        #Returns false if the command hasn't been executed yet
        def run?
                return false unless @process
                return true
        end
        #Returns the exit code for the command. Runs the command if it hasn't
run yet.
        def exitcode
                run unless @process
                @process.exitstatus
        end
        #Returns true if the command was succesfull.
        #
        #Will return false if the command hasn't been executed
        def success?
                return @process.success? if @process
                return false
        end
end

--
http://www.braveworld.net/riva

Sadly, system seems to be broken many ways on windows.

You can do it like this:

ExecCmd.new("rake"){|cmd|
        puts cmd.success?
        puts cmd.output

cmd=ExecCmd.new("rake")
cmd.run
puts cmd.success?
puts cmd.output

But a nice sideeffect of this implementation was
cmd1=ExecCmd.new("blabla")
cmd2=ExecCmd.new("blabla2")
cmd3=ExecCmd.new("blabla3")
[cmd1,cmd2,cmd3].each{|cmd|
        cmd.run
        #do stuff with it

On windows:
---------------------------
D:\temp>rake
rake aborted!
No Rakefile found (looking for: rakefile, Rakefile, rakefile.rb,
Rakefile.rb)
c:/unix/ruby/lib/ruby/gems/1.8/gems/rake-0.6.2/lib/rake.rb:1373:in
`load_rakefile'
D:\temp>irb
irb(main):001:0> system 'rake'
=> false
---------------------------

I think I know how this happens and everything (having done quite some c
programming on windows), its just that I think that it breaks
expectations. I hope I could illustrate my point.

Looks like as soon as you have a pipe in the command, cmd.exe is invoked
correctly: system 'echo | rails'. I came up with this after digging trough
to the actual implementation and nosing around for quite a time ;) .. its
of course nonsensical.

k

At Fri, 25 Nov 2005 06:21:03 +0900,
snacktime wrote in [ruby-talk:167407]: