[[:alnum:]] = [a-zA-Z0-9]
root@PC1:/home/test/test# ls a.txt root@PC1:/home/test/test# cat a.txt GMM 201 0 0 0 GMM 202 0 0 0 GMM 203 0 0 0 root@PC1:/home/test/test# sed 's/\(^[[:alnum:]]\+\)\t\([[:alnum:]]\+\)\t.*/\1\t\2\t\1/' a.txt ## [[:alnum:]]同时匹配数字和字母,结合sed预存储 GMM 201 GMM GMM 202 GMM GMM 203 GMM