On Thu, Feb 04, 2010 at 11:54:51PM -0600, Evan Driscoll wrote: > Why not make Bash consider \r\n a legitimate line ending? What possible > reason could there be for treating carriage return characters as it does > now?
Well, the most literal reason is that the shebang (#!/program) line will not work with a carriage return. This line is read as a comment by bash, but as a "use this program" directive by the underlying OS. The OS is going to try to run $'/program\r' and will not find it. Unless of course you made $'bash\r' a symlink to bash, and so on. Apart from that, there's no reason a Cygwin-style shell option couldn't be used on Unix. Other than, of course, the fact that it's a grossly bad habit to let yourself fall into; and the fact that no other shell would ever be able to read the script; and the 40 years of precedent for the current behavior....
