From: joemac <joemacbusiness@...>
Date: 2010-01-30T09:50:44+09:00
Subject: How do I use a variable in a regexp search string?

Hi All,

I dont know how to use a variable in a regex searchstring.
ruby seems to only handle hardcoded serachstring in
regex's.   How do you do this.   My code is below.

Also - how do you put a variable name in a
File.open("filename.txt") statement like this:
File.open(filevariable) where filevariable can
be set to anything?   I could not find this in
the docs.

Thanks, --Joe
================ snip code ===============
#!/usr/bin/ruby

F   = "filename.txt"
searchstring = ARGV[0]

print "searchstring is ", searchstring, "\n"


File.open("filename.txt").each { |line|
# this fails    puts line if line =~ searchstring
# this fails    puts line if line =~ /searchstring/
# this fails    puts line if line =~ "searchstring"

#this works
#    puts line
}