Guillaume Marcais
5/12/2005 10:40:00 PM
On Fri, 2005-05-13 at 06:00 +0900, Dany Cayouette wrote:
> Greetings,
> I'm pretty sure eval/proc/binding needs/can be used to solve my
> problem, but I'm having difficulty grasping those concepts.
>
> Given a series of shell scripts (bourne based) containing code such as
>
> FIRST=Dany
> LAST='Cayouette'
> FULLNAME="$FIRST $LAST"
> UID="danyc ($FULLNAME)"
>
> I would like to 'import' those value into a Ruby Hash such that the end
> result is something like
> {"LAST"=>"Cayouette", "UID"=>"danyc (Dany Cayouette)", "FULLNAME"=>"Dany
> Cayouette", "FIRST"=>"Dany"}
>
> So far I have
> class Hash
> def shparse (file)
> File.open(file, "r") do |f|
> while line = f.gets
> next unless line =~ /^\s*(\w+)=(.*)$/
> k = $1
> v = $2
> self[k] = v
> end
> end
> p self
> self
> end
> end
Two solutions to you problem. The first one shell_expand actually calls
the shell. So the expansion should be exactly what it is supposed to be.
But it is probably fragile: on my system, the variable UID is already
defined and read-only, and it would break shell_expand.
The other one tries to mimic the shell variable expansion in ruby. Of
course, not all the shell expansions are performed (as seen with
SHELL_ONLY).
$ cat shell-expand.rb
#!/usr/bin/ruby -w
script = <<EOT
FIRST=Dany
LAST='Cayouette'
FULLNAME="$FIRST $LAST"
UUID="danyc ($FULLNAME)"
EMPTY=
junk foo
SHELL_ONLY=$(date)
EOT
def shell_expand(script)
res = { }
io = open("|/bin/sh", "r+")
script.each { |l|
next unless l =~ /^(\w+)\s*=/
io.puts(l.chomp)
io.puts("echo $#{$1}")
res[$1] = (io.gets || "").chomp
}
res
end
def self_expand(script)
res = { }
script.each { |l|
next unless l =~ /^(\w+)\s*=\s*['"]?(.*?)['"]?$/
k, v = $1.strip, $2.strip
v = v.gsub(/\$(\w+)/) { |m| res[$1] || "" }
res[k.strip] = v
}
res
end
p shell_expand(script)
p self_expand(script)
$ ruby shell-expand.rb
{"EMPTY"=>"", "LAST"=>"Cayouette", "FULLNAME"=>"Dany Cayouette",
"SHELL_ONLY"=>"Thu May 12 18:33:56 EDT 2005", "UUID"=>"danyc (Dany
Cayouette)", "FIRST"=>"Dany"}
{"EMPTY"=>"", "LAST"=>"Cayouette", "FULLNAME"=>"Dany Cayouette",
"SHELL_ONLY"=>"$(date)", "UUID"=>"danyc (Dany Cayouette)",
"FIRST"=>"Dany"}
Hope it helps,
Guillaume.