Im trying to use gulp prompt:
message: 'Which task would you like to run?'
//value is in res.task (the name option gives the key)
gulp.src creates the stream of source files to perform the 'piped' operations on. In your example you're asking for a task to perform, which means you're asking what task to perform on the file
If you want to ask what task to perform, and then run one or more gulp tasks I think you'll need to write a plain old nodejs application that asks for the input and then start the
gulp [name of task] from there.