如何使用bash记录dmidecode结果

I have been trying to write a bash script to log dmidecode results in the a log file.

我一直在尝试编写一个bash脚本来记录日志文件中的dmidecode结果。

Till now, this is how far I got.

直到现在,这是我有多远。

#!/bin/bash

for i in `seq 0 5`; do
sudo su <<HERE
dmidecode -t $i >> system.log 
HERE

done

When I execute the above script, it asks for my password. As soon as I enter the password, I get the following error 6 times.

当我执行上面的脚本时,它会询问我的密码。输入密码后,我会收到以下错误6次。

bash: line 1: system.log: Permission denied

Anybody has any idea on how to solve this and log the dmidecode details. Any help is much appreciated. Thanks

任何人都知道如何解决这个问题并记录dmidecode细节。任何帮助深表感谢。谢谢

1 个解决方案

#1

Your command as written should work, but it can be simplified:

您编写的命令应该可以工作,但可以简化:

#!/bin/bash

for i in {0..5}; do
  sudo -s <<<"dmidecode -t $i >> system.log"
done

If the above doesn't work, let us know.

如果上述方法无效,请告知我们。

sudo -s takes a shell command to execute as root from stdin^[1], so there's no need for su; since the command is simple enough, I'm using a here-string (<<<) instead of a here-document.
- Note how the output redirection, >> system log, is part of the command string, as it would otherwise happen in the context of the current user:
  - sudo -s <<<"dmidecode -t $i" >> system.log would actually produce the error you describe, if you executed it in a directory in which the current user is not allowed to create files.
- The upshot is that the resulting system.log file will be owned by root.

sudo -s接受一个shell命令从stdin [1]以root身份执行,因此不需要su;由于命令很简单,我使用的是here-string(<<<)而不是here-document。注意输出重定向>>系统日志是命令字符串的一部分,否则会在当前用户的上下文中发生:sudo -s <<<“dmidecode -t $ i”>> system.log将实际产生您描述的错误,如果您在不允许当前用户创建文件的目录中执行它。结果是生成的system.log文件将由root拥有。

{0..5} uses a brace expansion to drive the iteration, which is more efficient.

{0..5}使用大括号扩展来驱动迭代,这样效率更高。

^{[1] sudo -s also accepts a command as additional arguments, but such a command passed this way is limited to simple commands without redirections, so it wouldn't work in this case.
Additionally, you cannot pass such a command as a single string, which requires passing - and quoting - its arguments individually.
Older versions of sudo - such as found on macOS up to 10.11 - did allow passing an entire shell command line as a single argument, but that should no longer be used - use stdin input.}

[1] sudo -s也接受一个命令作为附加参数,但是这样传递的命令仅限于没有重定向的简单命令,所以在这种情况下它不起作用。此外,您不能将这样的命令作为单个字符串传递,这需要单独传递 - 并引用 - 它的参数。较旧版本的sudo(例如在macOS上发现的最高10.11)确实允许将整个shell命令行作为单个参数传递,但不应再使用它 - 使用stdin输入。

#1