Catching line numbers in ruby exceptions
Solution 1:
p e.backtrace
I ran it on an IRB session which has no source and it still gave relevant info.
=> ["(irb):11:in `foo'",
"(irb):17:in `irb_binding'",
"/usr/lib64/ruby/1.8/irb/workspace.rb:52:in `irb_binding'",
"/usr/lib64/ruby/1.8/irb/workspace.rb:52"]
If you want a nicely parsed backtrace, the following regex might be handy:
p x.backtrace.map{ |x|
x.match(/^(.+?):(\d+)(|:in `(.+)')$/);
[$1,$2,$4]
}
[
["(irb)", "11", "foo"],
["(irb)", "48", "irb_binding"],
["/usr/lib64/ruby/1.8/irb/workspace.rb", "52", "irb_binding"],
["/usr/lib64/ruby/1.8/irb/workspace.rb", "52", nil]
]
( Regex /should/ be safe against weird characters in function names or directories/filenames ) ( If you're wondering where foo camefrom, i made a def to grab the exception out :
>>def foo
>> thisFunctionDoesNotExist
>> rescue Exception => e
>> return e
>>end
>>x = foo
>>x.backtrace
Solution 2:
You can access the backtrace from an Exception object. To see the entire backtrace:
p e.backtrace
It will contain an array of files and line numbers for the call stack. For a simple script like the one in your question, it would just contain one line.
["/Users/dan/Desktop/x.rb:4"]
If you want the line number, you can examine the first line of the backtrace, and extract the value after the colon.
p e.backtrace[0].split(":").last