Count the appearence of certain chars
using perl's string-operator
#!/usr/bin/perl # Count the appearence of certain chars using regular expression query # $string="MNVDPFSPHSSDSFAQAASPARKPPRGGRRIWSGTREVIAYGMPASVWRDLYYWALKVSWPVFFASLAALFVVNNTLFALLYQLGDAPIANQSPPGFVGAFFFSVETLATVGYGDMHPQTVYAHAIATLEIFVGMSGIALSTGLVFARFARPRAKIMFARHAIVRPFNGRMTLMVRAANARQNVIAEARAKMRLMRREHSSEGYSLMKIHDLKLVRNEHPIFLLGWNMMHVIDESSPLFGETPESLAEGRAMLLVMIEGSDETTAQVMQARHAWEHDDIRWHHRYVDLMSDVDGMTHIDYTRFNDTEPVEPPGAAPDAQAFAAKPGEGDARPV"; $neg = ($string =~ tr/[DE]//); $pos = ($string =~ tr/[RK]//); $his = ($string =~ tr/[H]//); $total = $pos+$his-$neg; $totalNoHis = $pos-$neg; print "NEG = $neg ; POS = $pos ; HIS = $his; TOT = $total (without HIS = $totalNoHis)\n";