filter/*.pl の sub filter ($$$$) の行を見つけて、その $ の数を表示する:

ttyp1:makoto@mini 10:36:00/070930(...local-src/namazu-2.0.17)> 
   foreach i ( filter/*.pl )
foreach? grep 'sub filter ' $i |   \
   perl -nle '$_=~ /([\$]+)/; print $1' | wc | tr -d '\012' 
foreach? echo ' ' $i
foreach? end
       1       1       6  filter/apachecache.pl
       1       1       6  filter/bzip2.pl
       1       1       6  filter/compress.pl
       1       1       6  filter/deb.pl
       1       1       6  filter/dvi.pl
       1       1       6  filter/excel.pl
       1       1       6  filter/gnumeric.pl
       1       1       6  filter/gzip.pl
       1       1       6  filter/hdml.pl
       1       1       6  filter/hnf.pl
       1       1       6  filter/html.pl
       1       1       6  filter/koffice.pl
       1       1       6  filter/macbinary.pl
       1       1       6  filter/mailnews.pl
       1       1       6  filter/man.pl
       1       1       6  filter/mhonarc.pl
       0       0       0  filter/mp3.pl
       1       1       6  filter/msofficexml.pl
       1       1       6  filter/msword.pl
       1       1       6  filter/ooo.pl
       1       1       6  filter/pdf.pl
       1       1       6  filter/pipermail.pl
       1       1       6  filter/postscript.pl
       1       1       6  filter/powerpoint.pl
       1       1       6  filter/rfc.pl
       1       1       6  filter/rpm.pl
       1       1       6  filter/rtf.pl
       1       1       6  filter/taro.pl
       1       1       6  filter/taro56.pl
       0       0       0  filter/taro7_10.pl
       1       1       6  filter/tex.pl
       1       1       6  filter/visio.pl
       1       1       6  filter/zip.pl
ttyp1:makoto@mini 10:36:11/070930(...local-src/namazu-2.0.17)> 

こっちの方が分り易いし簡単だ:

ttyp1:makoto@mini 10:50:33/070930(...local-src/namazu-2.0.17)> foreach i ( filter/*.pl )
foreach? grep 'sub filter ' $i | tr -d '\012'
foreach?  echo ' ' $i
foreach? end
sub filter ($$$$$) {  filter/apachecache.pl
sub filter ($$$$$) {  filter/bzip2.pl
sub filter ($$$$$) {  filter/compress.pl
sub filter ($$$$$) {  filter/deb.pl
sub filter ($$$$$) {  filter/dvi.pl
sub filter ($$$$$) {  filter/excel.pl
sub filter ($$$$$) {  filter/gnumeric.pl
sub filter ($$$$$) {  filter/gzip.pl
sub filter ($$$$$) {  filter/hdml.pl
sub filter ($$$$$) {  filter/hnf.pl
sub filter ($$$$$) {  filter/html.pl
sub filter ($$$$$) {  filter/koffice.pl
sub filter ($$$$$) {  filter/macbinary.pl
sub filter ($$$$$) {  filter/mailnews.pl
sub filter ($$$$$) {  filter/man.pl
sub filter ($$$$$) {  filter/mhonarc.pl
  filter/mp3.pl
sub filter ($$$$$) {  filter/msofficexml.pl
sub filter ($$$$$) {  filter/msword.pl
sub filter ($$$$$) {  filter/ooo.pl
sub filter ($$$$$) {  filter/pdf.pl
sub filter ($$$$$) {  filter/pipermail.pl
sub filter ($$$$$) {  filter/postscript.pl
sub filter ($$$$$) {  filter/powerpoint.pl
sub filter ($$$$$) {  filter/rfc.pl
sub filter ($$$$$) {  filter/rpm.pl
sub filter ($$$$$) {  filter/rtf.pl
sub filter ($$$$$) {  filter/taro.pl
sub filter ($$$$$) {  filter/taro56.pl
  filter/taro7_10.pl
sub filter ($$$$$) {  filter/tex.pl
sub filter ($$$$$) {  filter/visio.pl
sub filter ($$$$$) {  filter/zip.pl
ttyp1:makoto@mini 10:50:45/070930(...local-src/namazu-2.0.17)>

mp3 と taro7_10.pl は sub filter($$$$$) のように ( の前に空白文字がないのが原因