w -h|grep -q “^$username” || { echo $username do not login;exit 1;}
时间: 2024-05-24 22:12:05 浏览: 14
This is a shell script command that checks whether a user with the given username is allowed to login.
Explanation:
- `w` command displays information about currently logged in users
- `-h` option disables printing of header
- `grep` command searches for a pattern in text and returns the lines that match the pattern
- `^` in the pattern represents the beginning of the line
- `$username` is the pattern to search for, which matches the username variable passed to the script
- `||` is a logical OR operator
- `{}` curly braces group multiple commands and allow for conditional execution
- `echo` command prints a message to the console
- `exit` command terminates the script with an exit code
Overall, the command checks if the username is present in the output of the `w` command. If it is not found, the script prints a message saying the user cannot login and exits with a non-zero status code (indicating an error).
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