Let’s do a simple experiment, to check the Internet connection between the user’s computer and a set of IPs by a shell script. The basic command tool is Ping which sends packets to network hosts. It will receive a network response in a short time if the Internet connection is Read more…
Initial developing environment: “C:Program Files (x86)Microsoft Visual Studio 12.0VCvcvarsall.bat” x86 Use cmake to generate a project file. E:projectprivatedoubleView2>cmake ./ — Building for: Visual Studio 16 2019 — Selecting Windows SDK version 10.0.17763.0 to target Windows 10.0.17134. — The C compiler identification is MSVC 19.21.27702.2 — The CXX compiler identification is Read more…
notes ${} 和 $[] $[expression] can calculate easily. ${expression} can tell us the value of a element in array. eg val1=23 val2=24 echo $val1+$val2 echo $[$val1+$val2] #it is equal to `echo $(( $val1+$val2 )` [edemon@CentOS workspace]$ ./incalc.sh 23+24 47 assign values to array. array=(`echo {1..10}`) echo ${array[0]}” “${array[9]} [edemon@CentOS workspace]$ Read more…
SHA is a series of encrypting algorithm which includes sha1, sha256, sha512 and so on. They calculate a checksum based on a file or text string. We can use the result to judge whether two objects are the same. There is a terminal tool called shasum on Unix style operating Read more…