Load "/proc/self/fd/#{$stdin.fileno}"

ruby-talk
1

Hello,

the Ruby code in this article's subject works for my machine running
Ubuntu Linux, but I don't expect it to work for different operating
systems (NetBSD, FreeBSD a.s.o.).

How can alternative OS independent Ruby code look like? Of course, it
shall also load from standard input rather than from a file. Despite
that, it shall be very close to loading a "real" file, e.g.: the line
number of the error location shall be told in case of a syntax error
within the loaded code.

Regards
  Thomas

2

$ cat foo.rb
eval $stdin.read
$ echo "puts 'this is great' "| ruby ./foo.rb
this is great

···

On Sat, Apr 18, 2009 at 7:00 PM, Thomas Hafner <thomas@faun.hafner.nl.eu.org> wrote:

Hello,

the Ruby code in this article's subject works for my machine running
Ubuntu Linux, but I don't expect it to work for different operating
systems (NetBSD, FreeBSD a.s.o.).

How can alternative OS independent Ruby code look like? Of course, it
shall also load from standard input rather than from a file. Despite
that, it shall be very close to loading a "real" file, e.g.: the line
number of the error location shall be told in case of a syntax error
within the loaded code.

3

Thomas Hafner wrote:

Hello,

the Ruby code in this article's subject works for my machine running
Ubuntu Linux, but I don't expect it to work for different operating
systems (NetBSD, FreeBSD a.s.o.).

How can alternative OS independent Ruby code look like? Of course, it
shall also load from standard input rather than from a file. Despite
that, it shall be very close to loading a "real" file, e.g.: the line
number of the error location shall be told in case of a syntax error
within the loaded code.

Use #read and #eval instead of #load, and supply the file/line params to eval:

$ cat bar.rb
puts "in bar"

xfndksnf_syntax_error
$ cat foo.rb
file = "bar.rb"

data = File.read(file)

eval data, nil, "your text here", 0

$ ruby foo.rb
in bar
your text here:2: undefined local variable or method `xfndksnf_syntax_error' for main:Object (NameError)

···

--
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

4

Thanks to David and Joel!

Regards
  Thomas