Linux shell (./path/filename), pathfilename

Linux shell (./path/filename), pathfilename

In the/etc/profile file, there is a script:

If [-f/etc/bash. bashrc]; then./etc/bash. bashrcfi

What is the meaning of "dot + space + file" here?

1. If we want to execute a file, but this file is not executable, we need to use chmod u + x file_name to make the file executable.
2. But sometimes we do not want to change the execution permission of this file, but want to execute this file, you can use (point number -- space -- file name) to execute a script (only the root user can do this)