The configuration format is a blend of traditional rules and rsyslogspecific extensions. One rule of thumb is that anything beginning with a dollar sign ($) is an extension. 基本的rsyslogd配置文件是/etc/rsyslog.conf,但你会在其他目录中找到特定的配置,比如/etc/rsyslog.d。 配置格式是传统规则和rsys...
If the --use-backslash option appears earlier in the options, then a dollar sign or backslash may be included literally in an option string by preceding it with a backslash. If the --use-backslash option is not in effect, then backslashes are not treated specially, and there is no way t...
Once you’ve opened a shell, it should display a prompt at the top that usually ends with a dollar sign ($). On Ubuntu, that prompt should look like name@host:path$, and on Fedora, it’s [name@host path]$. If you’re familiar with Windows, the shell window will look something ...
The fundamental building blocks(建筑模块) are the regular expressions that match a single character. Most characters, including all letters and digits, are regular expressions that match themselves. Any meta-character(元字符) with special meaning may be quoted by preceding it with a backslash. The ...
Anchoring The caret ^ and the dollar sign $ are meta-characters that respectively match the empty string at the beginning and end of a line. The Backslash Character and Special Expressions The symbols \< and \> respectively match the empty string at the beginning and end of a word. The ...
Usernames may contain only lower and upper case letters, digits, underscores, or dashes. They can end with a dollar sign. Dashes are not allowed at the beginning of the username. Fully numeric usernames and usernames . or .. are also disallowed. It is not recommended to use usernames be...
uses back quotesinstead of the dollar sign and parentheses: ls -l `which cp` 等价于 ls –l $(which cp) It is also common to use escaping toeliminate the special meaning of a character in a filename. For example, it is possible to use characters in filenames that normally have specia...
You’ll have to enter your password once, and then you’ll be in sudo mode. You can tell that you’re in sudo mode because the dollar sign in te prompt will change to a hash sign: I only use Linux for administrative work, so I always use the account with my name on it. However...
Most meta-characters lose their special meaning inside bracket expressions. To include a literal ] place it first in the list. Similarly, to include a literal ^ place it anywhere but first. Finally, to include a literal - place it last. Anchoring The caret ^ and the dollar sign $ are ...
The first line in the script file can be used to dictate which shell will be used to run the script. This is the meaning of the first line found in all of the script examples:#!/bin/bashWhy Use Shell Scripts?Depending on your background, you may not see any immediate value to ...