An important addition to the use of (s)printf because it is not used everyday (but you can read it in the excellent tutorial Using (s)printf() by reptile). In order to enforce a field width of e.g. 3 for a string you have to use:

printf "%3.3s\n", 'Ho';
printf "%3.3s\n", 'Hogfather'
printf "%3s\n",   'Hogfather';

# this prints 
 Ho
Hog
Hogfather
[download]

Just using %3s does not enforce the maximum length of the field - and btw pack doesn't have these 'problems'.

Update: Of course maybe it's not such a good idea to silently throw away part of the fields - so you should check the length of them beforehand. But this depends on your purpose ...

-- Hofmator