The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software library. This weakness allows stealing the information protected, under normal conditions, by the SSL/TLS encryption used to secure the Internet. SSL/TLS provides communication security and privacy over the Internet for applications such as web, email, instant messaging (IM) and some virtual private networks (VPNs).

Speed memory access by arranging data to take advantage of CPU caching.

realloc story

placement new syntax

valgrind can run a gdb server so that a gdb can interact with it. valgrind has 2 options to trigger that:

--vgdb=yes,
--vgdb-error=0.

This second option tells valgrind it needs to wait for that many errors before freezing and wait for a gdb to connect. Setting it to 0 will make valgrind to wait for gdb to connect before executing the program.

valgrind --vgdb=yes --vgdb-error=0 ./foo
gdb ./foo
(gdb) target remote | vgdb

Linux command shelf is a quick reference guide for all linux user who wish to learn linux commands. Commands are divided into 15 categories , which would be more easier to understand what commands to be used in specific requirement. The pdf format of linux command shelf is also available

lsof -nPi tcp:80

sed '/test/{/error|critical|warning/d}' somefile

!:1-3

shopt -s autocd

nocache <I/O-heavy-command>

lsmod | perl -e 'print "digraph \"lsmod\" {";<>;while(<>){@=split/\s+/; print "\"$[0]\" -> \"$\"\n" for split/,/,$[3]}print "}"' | dot -Tpng | display -

strace -e write=1,2 -p $PID 2>&1 | sed -un "/^ |/p" | sed -ue "s/^.{9}(.{50}).+/\1/g" -e 's/ //g' | xxd -r -p

strings /dev/mem|less

command !(regexp to remove from matching)

Note: This is a feature of bash, and it only works if you've enabled 'extglob' (Extended Pattern Matching):
shopt -s extglob

ifconfig | convert label:@- ip.png

ctrl-x e

Next time you are using your shell, try typing ctrl-x e (that is holding control key press x and then e). The shell will take what you've written on the command line thus far and paste it into the editor specified by $EDITOR. Then you can edit at leisure using all the powerful macros and commands of vi, emacs, nano, or whatever.