perl -e '$/ = "\n"; $_ = "str\015\012"; chomp; s/(\s)/sprintf("%o",ord($1))/eg; print $_,$/'

# prints "str15"

perl -e '$/ = "\r\n"; $_ = "str\015\012"; chomp; s/(\s)/sprintf("%o",ord($1))/eg; print $_,$/'

# prints "str"

perl -e '$/="\r\n"; $_ = "foo\015\012str\015\012"; chomp; s/(\s)/sprintf("%o",ord($1))/eg; print $_,$/'

# prints "foo1512str"