从 Bash 脚本写入自定义日志文件

Write to custom log file from a Bash script

提问by coffeemonitor

In Linux, I know how to write a simply message to the /var/log/messagesfile, in a simple shell script I created:

在 Linux 中，我知道如何/var/log/messages在我创建的一个简单的 shell 脚本中向文件写入一条简单的消息：

#!/bin/bash
logger "have fun!"

I want to stop throwing messages into the default /var/log/messagesfile, and create my own.

我想停止将消息扔到默认/var/log/messages文件中，并创建我自己的。

I tried this:

我试过这个：

#!/bin/bash
logger "have more fun" > /var/log/mycustomlog

It still logs to /var/log/messages. It did create the /var/log/mycustomlog, but it's empty.

它仍然登录到/var/log/messages. 它确实创建了/var/log/mycustomlog，但它是空的。

Anyone see what I'm missing?

有人看到我缺少什么吗？

采纳答案by Ansgar Wiechers

loggerlogs to syslog facilities. If you want the message to go to a particular file you have to modify the syslog configuration accordingly. You could add a line like this:

logger日志到系统日志设施。如果您希望消息转到特定文件，则必须相应地修改 syslog 配置。你可以添加这样的一行：

local7.*   -/var/log/mycustomlog

and restart syslog. Then you can log like this:

并重新启动系统日志。然后你可以像这样登录：

logger -p local7.info "information message"
logger -p local7.err "error message"

and the messages will appear in the desired logfile with the correct log level.

并且消息将以正确的日志级别出现在所需的日志文件中。

Without making changes to the syslog configuration you could use loggerlike this:

在不更改 syslog 配置的情况下，您可以logger像这样使用：

logger -s "foo bar" 2>> /var/log/mycustomlog

That would instruct loggerto print the message to STDERR as well (in addition to logging it to syslog), so you could redirect STDERR to a file. However, it would be utterly pointless, because the message is already logged via syslog anyway (with the default priority user.notice).

这也会指示logger将消息打印到 STDERR（除了将其记录到 syslog 之外），因此您可以将 STDERR 重定向到一个文件。但是，这完全没有意义，因为无论如何该消息已经通过系统日志记录了（具有默认优先级user.notice）。

回答by coffeemonitor

@chepner make a good point that loggeris dedicated to logging messages.

@chepner 提出了一个logger专门用于记录消息的好点。

I do need to mention that @Thomas Haratyk simply inquired why I didn't simply use echo.

我确实需要提到@Thomas Haratyk 只是询问我为什么不简单地使用echo.

At the time, I didn't know about echo, as I'm learning shell-scripting, but he was right.

当时，我不知道回声，因为我正在学习shell-scripting，但他是对的。

My simple solution is now this:

我的简单解决方案现在是这样的：

#!/bin/bash
echo "This logs to where I want, but using echo" > /var/log/mycustomlog

The example above will overwrite the file after the >

上面的例子将覆盖 > 之后的文件

So, I can append to that file with this:

所以，我可以用这个附加到该文件：

#!/bin/bash
echo "I will just append to my custom log file" >> /var/log/customlog

Thanks guys!

谢谢你们！

• on a side note, it's simply my personal preference to keep my personal logs in /var/log/, but I'm sure there are other good ideas out there. And since I didn't create a daemon, /var/log/probably isn't the best place for my custom log file. (just saying)

• 附带说明一下，保留个人日志只是我个人的偏好/var/log/，但我相信还有其他好主意。而且由于我没有创建守护程序，因此/var/log/可能不是我的自定义日志文件的最佳位置。（只是说）

回答by Piyush Chordia

There's good amount of detail on logging for shell scripts via global varaibles of shell. We can emulate the similar kind of logging in shell script: http://www.cubicrace.com/2016/03/efficient-logging-mechnism-in-shell.htmlThe post has details on introdducing log levels like INFO , DEBUG, ERROR. Tracing details like script entry, script exit, function entry, function exit.

关于通过 shell 的全局变量记录 shell 脚本的大量细节。我们可以在 shell 脚本中模拟类似的日志记录：http://www.cubicrace.com/2016/03/efficient-logging-mechnism-in-shell.html 这篇文章详细介绍了 INFO、DEBUG、错误。跟踪详细信息，如脚本入口、脚本出口、函数入口、函数出口。

Sample Log:

示例日志：

回答by pallav_rus

If you see the man page of logger:

如果您看到记录器的手册页：

$ man logger

LOGGER(1) BSD General Commands Manual LOGGER(1)

NAME logger — a shell command interface to the syslog(3) system log module

SYNOPSIS logger [-isd] [-f file] [-p pri] [-t tag] [-u socket] [message ...]

DESCRIPTION Logger makes entries in the system log. It provides a shell command interface to the syslog(3) system log module.

LOGGER(1) BSD 通用命令手册 LOGGER(1)

NAME logger — syslog(3) 系统日志模块的 shell 命令接口

概要记录器 [-isd] [-f 文件] [-p pri] [-t 标记] [-u 套接字] [消息 ...]

描述 Logger 在系统日志中创建条目。它为 syslog(3) 系统日志模块提供了一个 shell 命令接口。

It Clearly says that it will log to system log. If you want to log to file, you can use ">>" to redirect to log file.

它清楚地表明它将登录到系统日志。如果要登录到文件，可以使用“>>”重定向到日志文件。

回答by shrewmouse

I did it by using a filter. Most linux systems use rsyslog these days. The config files are located at /etc/rsyslog.confand /etc/rsyslog.d.

我是通过使用过滤器做到的。现在大多数 linux 系统都使用 rsyslog。配置文件位于/etc/rsyslog.conf和/etc/rsyslog.d。

Whenever I run the command logger -t SRI some message, I want "some message" to only show up in /var/log/sri.log.

每当我运行命令时logger -t SRI some message，我都希望“一些消息”只出现在/var/log/sri.log.

To do this I added the file /etc/rsyslog.d/00-sri.confwith the following content.

为此，我添加了/etc/rsyslog.d/00-sri.conf具有以下内容的文件。

# Filter all messages whose tag starts with SRI
# Note that 'isequal, "SRI:"' or 'isequal "SRI"' will not work.
#
:syslogtag, startswith, "SRI" /var/log/sri.log

# The stop command prevents this message from getting processed any further.
# Thus the message will not show up in /var/log/messages.
#
& stop

Then restart the rsyslogd service:

然后重启rsyslogd服务：

systemctl restart rsyslog.service

Here is a shell session showing the results:

这是一个显示结果的 shell 会话：

[root@rpm-server html]# logger -t SRI Hello World!
[root@rpm-server html]# cat /var/log/sri.log
Jun  5 10:33:01 rpm-server SRI[11785]: Hello World!
[root@rpm-server html]#
[root@rpm-server html]# # see that nothing shows up in /var/log/messages
[root@rpm-server html]# tail -10 /var/log/messages | grep SRI
[root@rpm-server html]#