I want to write a system call interposition by using Utrace. I understood that Utrace project has been abandoned, but part of its code is used on kprobe and uprobe. I haven’t understood really well how these work. Especially uprobe Can you explain what difference exists between them? And can I use uprob…
Bash terminal and color output [closed]
Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Stack Overflow. Closed 10 years ago. Improve this question I have a shell with colors enabled: somefile contains escape characters for coloring. Now I want t…
Octave strcat ignores added spaces
Octave adds spaces with strcat In Octave I run these commands: I get this result: Instead of what I expected: strcat to me sounds like “concatenate strings”. A space is a valid character, so adding a space should be OK. Matlab has the same behaviour, so it’s probably intended. I find it coun…
How do I detect when a Dropbox folder has been updated?
I have a folder with files that are being sychronized between computers. After the files have been uploaded from computer A, I would like to copy them from computer B’s Dropbox folder to another folder. How can I detect when the Dropbox folder has been updated? I can check the Dropbox folder periodicall…
New linux kernels, no lsm using lkms, no kernel hooks now what?
For security reasons, the kernel ceased to export characters necessary for writing security modules in the form of loadable kernel modules (Linux Kernel Module, LKM) starting with version 2.6.24. And you can’t export sys_call_table, again for security reasons. But then, how can I filter filesystem reque…
how to get size of folder including apparent size of sparse files? (du is too slow)
I have a folder containing a lot of KVM qcow2 files, they are all sparse files. Now I need to get the total size of folder, the qcow2 file size should be counted as apparent size(not real size). for example: image: c9f38caf104b4d338cc1bbdd640dca89.qcow2 file format: qcow2 virtual size: 100G (107374182400 byte…
Externalizing Tomcat webapp config from .war file
I am having trouble with configuring a webapp in Tomcat 7. In my WAR file, there is a properties file myApp/WEB-INF/classes/myProps.props, and it contains environment-specific properites. I am trying to override that configuration file on the server, so that the same WAR file will deploy to multiple environme…
Recursion using main() function [closed]
It’s difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 10 years ago. I am writing a prog…
Why can the value of the symbol returned by dlsym() be null?
In Linux. Per the dlsym(3) Linux man page, Why is this, when can a symbol (for a function, specifically) be actually NULL? I am reviewing code and found a piece using dlerror to clean first, dlsym next, and dlerror to check for errors. But it does not check the resulting function from being null before callin…
Use of floating point in the Linux kernel
I am reading Robert Love’s “Linux Kernel Development”, and I came across the following passage: No (Easy) Use of Floating Point When a user-space process uses floating-point instructions, the kernel manages the transition from integer to floating point mode. What the kernel has to do when us…