The syntax is:
PATH can be /aa , . , /aa/bb etc..
/aa means directory aa starting from / (see / as the root of a tree). aa is a direct leaf of the root.
/aa/bb means go in the directory aa under / and then again in bb
. is a synonym for the current directory
.. is a synonym for the parent directory ( /aa/.. is equivalent to /)
In case "PATH/" is not present, it is equivalent to
~$ cat: /morecols-0.3.5.1.xpi: No such file or directory
bash: cat:: command not found
~$ cat .morecols-0.3.5.1.xpi
cat: .morecols-0.3.5.1.xpi: No such file or directory
First command: /moreblabla defines a file which has PATH= / , name =moreblabla.
It means the file has to be at the root of the disk but I guess it's in your directory.
You forgot the / : .moreblabl is a file in the current directory with name .moreblabla. unfortunatly your file is moreblabla (without the dot)
So it's either
Your shell will execute the first argument. Above it was "cat" which displays the second argument (moreblabla)
If you want to execute a script, you then have to pass it as first argument.
BUT in your case, morecols-0.3.5.1.xpi is not possible to be executed from command line, it's a "plugin" for firefox: the suffix is "xpi".