提取两个逗号之间的字符？

Question

我有一个大约有 300 万行的文件，这是我文件的前几行：

head out.txt
    NA
    NA
    NA
    NA
    NA
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753,gene85754
    gene85752,gene85753,gene85754
    gene85752,gene85753,gene85754
    gene85752,gene85753,gene85754
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752,gene85753
    gene85752
    gene85752

对于那些由“,”分隔的行，我想保留第一个逗号之后和第二个逗号之前的所有内容。这是我想要的输出：

outgood.txt
NA
NA
NA
NA
NA
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85753
gene85752
gene85752

Answer 1

由于cut默认情况下打印非分隔行，因此以下工作

cut -f2 -d, file