Use hcitool to get Bluetooth device information

Below commands are shown for communication between Linux Laptop and Samsung Mobile to get Mobile bluetooth device information using hcitool. For this, first make sure laptop bluetooth is turned ON and then switch ON the Bluetooth of Mobile and Make it discoverable/visible to all nearby bluetooth devices. Lets try to understand what is hcitool, hcitool … Read more

Monitor Memory, CPU usage, processes i.e. system resources on Linux


System administrators need to monitor their server to ensure proper functioning. The practice enables administrators to detect possible issues in advance and recover the system, before it causes any trouble. There are plenty of commands on Linux to monitor different system resources like cpu usage, memory usage, network, disk usage and so on. Popular ones … Read more

How to Check Memory Usage in Linux using SMEM ?


smem is a tool that can give numerous reports on memory usage on Linux systems. Unlike existing tools, smem can report proportional set size (PSS), which is a more meaningful representation of the amount of memory used by libraries and applications in a virtual memory system. Because large portions of physical memory are typically shared among multiple applications, … Read more

Online tools for Software Developers from ExtendsClass

The ExtendsClass website provides a wealth of free online tools that make work-life easier for developers. No need to install plugin in your browser! Online tools include several fiddles, API clients, code checkers, formatters, validators and more. Within this post we will list some of the more helpful of its utilities. Playgrounds ExtendsClass provides many … Read more

How to record and replay Linux terminal commands ?

If you want to capture something like commands when you are installing some software, compiling some opensource codes or just want to see debug logs printed on the terminal by some program, there is command “script” which does all the work very efficiently for us. Just open a terminal, and type below command before you … Read more

Meaning of “CONTENTS, ALLOC, LOAD, READONLY, CODE” in ELF sections

Once we disassembled the ELF to check the sections using “objdump” command, we can see the lines as “CONTENTS, ALLOC, LOAD, READONLY, CODE” along with sections. In this post, we describe the meaning of each of this. You can also check “How to check sections and its memory map of Binary / ELF using GDB … Read more

How to check sections and its memory map of Binary / ELF using GDB ?

In this post, we hope you already have GDB debugging setup already done for your development or you can also simulate GDB debugging for ARM by following “Debugging ARM binary on Ubuntu Host using qemu ARM and GDB” Once you are in GDB console, we can check the details of sections of ELF running on … Read more

How to use mtrace to detect memory leaks in executable in Linux ?

The mtrace() function installs hook functions for the memory- allocation functions malloc, realloc, memalign, free. These hook functions record tracing information about memory allocation and deallocation. The tracing information can be used to discover memory leaks and attempts to free nonallocated memory in a program. We will create a simple program as below, Note here: … Read more

What is the difference between elfutils and binutils ?

As per wikipedia, elfutils is mentioned as, “Ulrich Drepper wrote elfutils, to replace GNU Binutils, purely for Linux and with support only for ELF and DWARF” elfutils is a Red Hat project. There is substantial overlap between elfutils (eu-addr2line, eu-elflint, eu-findtextrel, eu-nm, eu-readelf, eu-size, eu-strip, etc.) and binutils (addr2line, nm, readelf, size, strip, objdump, etc.) … Read more