ruby - How do I execute Date from a string? -

i trying read file has dynamic dates in such date.today or (date.today - 1 ), , perform code based on date requested.

if have string defined date in quotes works. when reading same string file not. there eval function need use make work?

require 'date' #works abc = "something #{date.today}" puts abc # 2013-04-19  #does not work f = file.read("test.txt") f.each_line { |line|  puts line ; words = line.split("\t")   puts line } 

contents of test.txt file:

something #{date.today} # #{date.today} 

you're going have use eval evaluate contents of each line read.

but since evaluating arbitrary code have trust not malicious code.

so, assuming trust file , lines:

require 'date' f = file.read("test.txt") f.each_line |line|  puts eval("\"#{line}\"") end 

notice double-quote wrapping, "piece of code" evaluating needs "valid" ruby string (which in turn contains code, wrap in quotes make appear actual double-quoted string.

this works if test.txt looks like:

hello, #{date.today} goodbye, #{date.today}