$1=(a[$1]?a[$1]1; 會(huì)增加a數(shù)組元素,a[1], a[2], .. 也可以寫成這樣:$1=($1 in a)?a[$1]1;
$ awk 'BEGIN{FS=OFS=":"} FNR==NR{if ($2!=$1) a[$1]=$2} FNR<NR{$1=a[$1]?a[$1]:$1;print}END{print "---Hash--------";for (i in a) print i":\t\""a[i]"\""}' B A
1:a
2:b
4:c
5:d
3:e
---Hash--------
: ""
4: "5"
5: "3"
1: ""
2: ""
3: "4"
$ awk 'BEGIN{FS=OFS=":"} FNR==NR{if ($2!=$1) a[$1]=$2} FNR<NR{$1=($1 in a)?a[$1]:$1;print}END{print "---Hash--------";for (i in a) print i":\t\""a[i]"\""}' B A