The format for the numeric prefix. This is passed to
sprintf()
. The default format is "%0Nd"
where N
= floor(log10(n)) + 1
and n
is the number of files, which means the
prefix may be padded with zeros. For example, if there are 150 files to be
renamed, the format will be "%03d"
and the prefixes will be
001
, 002
, ..., 150
.