Standard I/O and plumbing exercises

1. Convert the contents of the/etc/issue file to uppercase and save to the/tmp/issue.out file

2. Convert the current system login user's information to uppercase and save to the/tmp/who.out file

3, a Linux user to the root email, request the message titled "Help", the message body is as follows: Hello, I am user name, the system version is Here,please help me to check it, thanks! Operating system Version Information

4, the/root/file list, displayed as a line, and the file name separated by a space

5. The contents of the File1 file are: "1 2 3 4 5 6 7 8 9 10" Calculates the sum of all numbers

6. Delete the ' ^m ' character 7 in the Windows text file, handle the string "Xt.,l 1 jr#! $mn 2 c*/fe 3 uz 4" and keep only the numbers and spaces

8. Display the path variable in a separate row for each directory

9. Delete blank lines of the specified file

10. Display each word (letter) in the file in a separate line with no blank lines

This article is from the "Bread" blog, be sure to keep this source http://daliu.blog.51cto.com/4051113/1834548

Standard I/O and plumbing exercises