perl -e "print sort {chomp($x=$a); chomp($y=$b); $x cmp $y} <>" file.txt

The following is also a bit challenged in the beauty stakes but avoids the repetitive chomp'ing of the lines. Tested under both M$ shell (with double quotes) and Solaris ksh (with single-quotes).

perl -e "print map{qq{$_$/}} sort map{chomp; $_} <>;" file.txt
[download]

I hope this is of interest.

Cheers,

JohnGG