For starters, printf is NOT a slide-in substitute for print.

C:\>perldoc -f printf
    printf FILEHANDLE FORMAT, LIST
    printf FILEHANDLE
    printf FORMAT, LIST
    printf  Equivalent to "print FILEHANDLE sprintf(FORMAT, LIST)", ex
+cept
            that $\ (the output record separator) is not appended. The
+ first
            argument of the list will be interpreted as the "printf" f
+ormat.
            See "sprintf" for an explanation of the format argument. I
+f you
            omit the LIST, $_ is used; to use FILEHANDLE without a LIS
+T, you
            must use a real filehandle like "FH", not an indirect one 
+like
            $fh. If "use locale" is in effect and POSIX::setlocale() h
+as
            been called, the character used for the decimal separator 
+in
            formatted floating-point numbers is affected by the LC_NUM
+ERIC
            locale setting. See perllocale and POSIX.

            Don't fall into the trap of using a "printf" when a simple
            "print" would do. The "print" is more efficient and less e
+rror
            prone.
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