fineした結果をループ処理しようとしたら一部replstrが展開されず。
なんでかなぁと思ったら xargsが255byteまでしか展開できない | ottijp blog
ということらしく
複数の場合は合算されるらしい。
macだけの仕様らしい。
man xargsから抜粋。
-I replstr
Execute utility for each input line, replacing one or more
occurrences of replstr in up to replacements (or 5 if no -R flag
is specified) arguments to utility with the entire line of input.
The resulting arguments, after replacement is done, will not be
allowed to grow beyond replsize (or 255 if no -S flag is
specified) bytes; this is implemented by concatenating as much of
the argument containing replstr as possible, to the constructed
arguments to utility, up to replsize bytes. The size limit does
not apply to arguments to utility which do not contain replstr,
and furthermore, no replacement will be done on utility itself.
Implies -x.