LAMP is short for Linux, Apache, MySQL, PHP. Of course, you already have a Linux OS (CentOS), so this article mainly introduces installation of Apache, MySQL and PHP. I need this environment because I use WordPress program which should run on basis of this environment.
Assume that you now want to use port 18080 to run your new program, but you find that the port is already employed by other program. What need you do? First, find the target program using the specific port (18080, in this case), then shut the program down to free the specific port.
chmod 754 myfile: This is equivalent to the command above. Here the digits 7, 5, and 4 each individually represent the permissions for the user, group, and others, in that order. Each digit is a combination of the numbers 4, 2, 1, and 0. 4 stands for "read", 2 stands for "write", 1 stands for "execute", and 0 stands for "no permission". So 7 is the combination of permissions 4+2+1 (read, write, and execute), 5 is 4+0+1 (read, no write, and execute), and 4 is 4+0+0 (read, no write, and no execute).
