P4ENVIRO vs P4CONFIG

On Windows p4 set puts vars in the registry. It's also possible to store variables in a file and point to it using P4ENVIRO or P4CONFIG

The only difference between the two is how files are found.P4ENVIRO requires a file in a specific location: P4ENVIRO=F:\path\to\file\p4config.txt

WhileP4CONFIGwill search parent directories (starting from CWD) for the file: P4CONFIG=p4config.txt

If your current working directory has no p4config.txt file then a p4 set on the CMD will return: P4CONFIG=p4config.txt (set) (config 'noconfig')

Which can confuse some people into thinking they don’t have it properly setup. However, if you switch to a workspace folder where the current or parent directories have the p4config.txt file, it will pick up and display the proper settings.

In summary, P4ENVIRO is used for centralized management of settings across workspaces for one project at a time. With P4CONFIG you can have settings files across workspaces for multiple projects. This makes switching p4 vars between projects easier.