Hi!
I'd like to make some kind of substitution like in a shell, i.e. having:
"${tool} -o ${target} -L${libpath} -l${lib} ${source}"
with an env like this:
env = {
"tool" => "gcc",
"target" => "hello.exe",
"libpath" => "/usr/lib",
"lib" => "somelib",
"source" => "hello.c"
}
it should give:
"gcc -o hello.exe -L/usr/lib -lsomelib hello.c"
It is easy until I want to manage caracter escapement like
"${var\\}weird}" which should give env["var}weird"], "\\${var}" which
should give the simple string "${var}" and "\\\\${var}" which should be
equivalent to "\\" + env["var"].
i don't think you need to worry about that since 'var}weird' is not a valid
shell identifier - at least i can't seem to create a var by that name in the
shell...
Any idea of how I could manage that?
you can get bash's exact parameter expansion like this:
jib:~ > cat a.rb
require 'session'
class Expander
def self::new(*a, &b)
@instance = super
end
def initialize
@bash = Session::Bash::new
end
def expand expr, context = {}
context.each do |k,v|
o, e = @bash.execute "#{ k }=#{ v }"
raise e unless e.empty?
end
stdout, stderr = @bash.execute "cat <<eos\n#{ expr }\neos"
raise stderr unless stderr.empty?
context.each{|k,v| @bash.execute "unset #{ k }"}
stdout.chomp
end
end
ex = Expander::new
expr = "${tool} -o ${target} -L${libpath} -l${lib} ${source}"
env = {
"tool" => "gcc",
"target" => "hello.exe",
"libpath" => "/usr/lib",
"lib" => "somelib",
"source" => "hello.c"
}
cmd = ex.expand expr, env
p cmd
jib:~ > ruby a.rb
"gcc -o hello.exe -L/usr/lib -lsomelib hello.c"
-a
···
On Thu, 14 Oct 2004, Lionel Thiry wrote:
--
EMAIL :: Ara [dot] T [dot] Howard [at] noaa [dot] gov
PHONE :: 303.497.6469
When you do something, you should burn yourself completely, like a good
bonfire, leaving no trace of yourself. --Shunryu Suzuki
===============================================================================
