awk 特征相同的行合并

[root@linux-node1 ~]# cat test.txt
  hisk01
  hisk02
  hisk03
  hisk04
  hisk05
  hisk06
  hisk07
  hisk08
[root@linux-node1 ~]# awk'{if($1==x){i=i" "$2}else{if(NR>1){print i};i=$0};x=$1;y=$2}'test.txt <(echo)
  hisk01hisk02 hisk03
  hisk04hisk05 hisk06
  hisk07hisk08
[root@linux-node1 ~]# awk'{a[$1]=a[$1]?a[$1]" "$2:$2}END{for(i=0;i++<asorti(a,b);)printb[i],a[b[i]]}' test.txt
 hisk01 hisk02 hisk03
 hisk04 hisk05 hisk06
 hisk07 hisk08