Remove all arbitary spaces before a line in Vim

Question

I\'v written a plugin where it comes to parsing a XML tag. The content inside the tag is indented and when i copy the parsed string into the file it\'s gettting like:

<

Answer 1

Yet another way to achieve this is using the the normal command :h :normal-range

:%norm d^

This goes to column 0 in each line (%) and deletes (d) to the first non-white character(^).

This is slightly more to type as the accepted answer, but allows for easy extension if you have a more complex scenario in mind, such as additional un-commenting or so:

:%norm d^I# 

Resulting in:

#Example line
#This is part of the parsed line
#Thats goes one
#End of line