[root@pc1 test01]#awk'{if(NR == FNR) {FS = ":"; print $2} else {FS = " "; print $1}}'a.txt b.txt512100A5042 。
$echo"abc[defg]higk"|awk-F"[][]"'{print $2}' $ defg 1 -F"[可以制定多个分隔符]"