Feature request: DOS line endings recognition

[Francesco Montorsi]

Hi,
    I've found out (after trying almost everything else I could coinceive), that if I 
make a BASH script with DOS/WIN line endings instead of UNIX line endings, when I try to 
run that script I get the error message:

: bad interpreter: No such file or directory

this is rather useless as error message: I understand this is because after reading the 
first CR character, BASH reads the LF character and (maybe?) try to exec it and then shows 
this error.

So, my proposal/feature-request is:

1) make a better error message when executing scripts with CRLF line endings (maybe using 
a simple heuristics to check if a script file has CRLF endings)

2) auto-convert internally scripts with DOS line endings to UNIX line endings

This was really a problem for me, specially because I have to copy & edit files among unix 
& win machines. Obviously, now that I've found the cause of the error, I just need to use 
"dos2unix" to fix the problem, but I think that a better error message / handling of DOS 
line endings could help a lot of other people... ;)

Francesco