Hi
Im trying to run an exe in another directory like this:
but when i do it says but when i go to bin first and then run the exe it works?
whats going wrong?

Welcome to LinuxQuestions.

The . in your command ./a.out is a shortcut for current working directory i.e. the directory the terminal is at the time you run the command. Most linux distributions do no include the current working directory in the path environment for security reasons which is why when you run the command you need to add ./

If you want to run the command from another directory that is not in your path environment you use the complete path i.e. /bin/a.out

Many distributions include /bin in a users path environment and therefore to run the command you just type in a.out. Although a.out is the default compiler program name and if you have more then one scattered throughout you may not execute the intended program.

Can you run the program when you call it by the complete /path/to/program?

...NM...

You don't have ./bin in your PATH statement.
Either add it, or use a full path to the file.

You can always run a prog (if it has x perms & correct ownerships) via relative or absolute paths, without having the dir in your PATH
NB: of course for shell scripts & similar it also needs 'r' perm.

It's the point/dot/period.

You want