China DOS Union

There are numbers with 11 digits in a.txt, such as:
12345678910
58156451511
62264545655
23331561615
21215121525

I want to take 10 digits and save them to b.txt. How to write it?

Best to tell the meaning of each sentence, thank you, everyone.

sed 's/$//g' a.txt

Replace the last digit with empty.

sed 's/\(*\)$/\1/g' a.txt

Group, the previous several digits as one group, the last digit as the second group, then use the first group to replace the whole string.

peter@ubuntu-maverick:~/temp$ cat a.txt

12345678910

58156451511

62264545655

23331561615

21215121525

peter@ubuntu-maverick:~/temp$ sed 's/\(*\)$/\1/g' a.txt

1234567891

5815645151

6226454565

2333156161

2121512152

[ Last edited by peterhuang on 2010-12-2 at 21:42 ]