Preparation Knowledge SSH is a very useful tool which supports to use all kinds of commands to control remote computer for developers. Before interacting with the server, users are required to login with a username and password to be certified. But it’s inconvenient for us to input password every time 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…