Count nul delimited items in file

Some options:

tr -cd '\0' | wc -c

tr '\n\0' '\0\n' | wc -l      # Generic approach for processing NUL-terminated
                              # records with line-based utilities (that support
                              # NUL characters in their lines like GNU ones).

grep -cz '^'                  # GNU grep

sed -nz '$='                  # recent GNU sed, no output for empty input

awk -vRS='\0' 'END{print NR}' # not all awk implementations

Note that for an input that contains data after the last NUL character (or non-empty input with no NUL characters), the tr approaches will always count the number of NUL characters, but the awk/sed/grep approaches will count an extra record for those extra bytes.

The best method I've been able to think of is using grep -zc '.*'. This works, but it feels wrong to use grep with a pattern which will match anything.