call_usermodehelper / call_usermodehelperpipe使用 [英] call_usermodehelper / call_usermodehelperpipe usage

问题描述

我已经按照从内核调用用户的应用程序这个伟大的文档：<一href=\"http://www.ibm.com/developerworks/linux/library/l-user-space-apps/index.html\">http://www.ibm.com/developerworks/linux/library/l-user-space-apps/index.html

I've followed this great document on invoking user apps from the kernel: http://www.ibm.com/developerworks/linux/library/l-user-space-apps/index.html

但我现在如何从已运行的应用程序的输出感兴趣。我试图传递重定向操作符写输出到文件..例如：

But I'm now interested in how to get the output from the apps that have been run. I tried passing in redirection operators to write the output to a file.. Eg:

char *argv[] = { "/usr/bin/ls", ">>", "/tmp/list", NULL};
call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);

没有这样的运气。我碰到 call_usermodehelperpipe 并想知道这将是我后，但我一直没能掌握如何使用它，或者找到像上述之一的任何文件就可以了。

No such luck. I came across call_usermodehelperpipe and wondered if that would be what I'm after, but I haven't been able to grasp how to use it or find any documents like the above one on it.

先谢谢您的建议/帮助！

Thanks in advance for suggestions / help!

推荐答案

＆GT;＆GT; 不是 LS参数，它是从外壳的东西。它可以通过解析 / bin / sh的-cLS＆GT;＆GT;的/ tmp /列表（带壳）。在C语言中，是这样的：

>> is not an argument for ls, it is something from the shell. It can be parsed using/bin/sh -c "ls >> /tmp/list" (in shell). In C, this is:

char *argv[] = { "/bin/bash", "-c", "/bin/ls >> /tmp/list", NULL};

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