sub a{$_=int$_[0]*10**$_[1];s;(.{$_[1]})$;\.$1;;return$_};

##</code><code>##

my @a = ("1.10", "2.22");
print STDOUT &a($_, 1) for @a;

sub a{$_=int$_[0]*10**$_[1];s;(.{$_[1]})$;\.$1;;return$_};

##</code><code>##

sub a{$_=int$_[0]*10**$_[1]+.5;s;(.{$_[1]})$;\.$1;;chop if substr($_,-1)eq'.';return$_};

##</code><code>##

value|precision     sprintf   Incognito   Albannach       jeffa      rob_au
 '123.45678'|3:     123.457     123.456     123.456         123     123.457
      '12.4'|1:        12.4        12.4        12.4          12        12.4
          ''|0:           0                                               0
      '3.14'|5:     3.14000     3.14000     3.14000    00003.14     3.14000
         '1'|5:     1.00000     1.00000     1.00000       00001     1.00000
        '.5'|0:           0                                               1
        '10'|5:    10.00000    10.00000    10.00000       00010    10.00000
  '12.45435'|0:          12          12          12          12          12
       '100'|5:   100.00000   100.00000   100.00000       00100   100.00000
        '3.'|0:           3           3           3           3           3
      '1000'|5:  1000.00000  1000.00000  1000.00000       01000  1000.00000
     '12.56'|0:          13          12          12          12          13