數由元素在Perl

Question

我有這樣一個文件：

fan  apple banana orange mango 
cooler apple orange banana mango 
cooler apple orange banana mango 
cooler apple orange banana mango 
fan  apple banana orange mango 
fan  apple banana orange mango 
cooler apple orange banana mango 
fan  apple banana orange mango 

現在，當我被行我想在那一刻來算，當風扇開始轉動，需要增加與每一個球迷指望去行。像

count 1 
fan  apple banana orange mango 
cooler apple orange banana mango 
cooler apple orange banana mango 
cooler apple orange banana mango 
count 2 
fan  apple banana orange mango 
count 3 
fan  apple banana orange mango 
cooler apple orange banana mango 
count 4 
fan  apple banana orange mango 

這就是我想要的輸出。幫助表示讚賞...謝謝你

Answer 1

#!/usr/bin/perl 
use strict; 
use warnings; 

my $n = 0; 
while (<>) { 
    print "count ", ++$n, "\n" if /^fan\b/; 
    print; 
} 

或使用Perl 5.10+一個班輪：

perl -pE 'say "count ", ++$n if /^fan\b/' 

Answer 2

在一個班輪：

perl -lane 'BEGIN{$c=1}; $F[0] eq "fan" && do{print "count ".$c++ }; print' file