Cat a text file (js) and assigned to the variables, but in the js file/* */comment content, in the cat out of the contents of the variable that is a lot more root directory and the file name under the current directory, should be in the process of the cat made a command execution of some js in the text? How to let the cat does not execute the commands in the text content?

Separate cat filename, not assigned to a variable is no problem, it is only to be assigned to the variable appears only when the problem,

Do not understand, consult, thank you!