How to concatenate JavaScript files without a build tool?

Question

In bash without using Ant, Grunt or similar, I want to concatenate some files.

I don't think is should be harder than a few lines of bash.

I don't want to use a build tool as they do in this SO Post.

I want to use bash similar to this SO Post.

It would be something like:

cat *.js > all.txt

However, I want to only cat .js files that have this form

object.SomeName.js

As a side question, do most people break out their .js into objects?

What about:

cat object.*.js >> all.txt

Also there are dependencies between the objects, so ordering matters.

What ordering does cat work in?

sounds like you just need to readup on wildcard file matching in bash... — dandavis
– dandavis, Commented Oct 4, 2015 at 21:27
I posted what I think is the answer, but b.c. there are depeddencies, I need to know the order that cat works in or perhaps there is a batter bash tool? — cade galt
– cade galt, Commented Oct 4, 2015 at 21:28
This answer: serverfault.com/a/122743 says bash wildcard expansion is alphabetical. — jjrv
– jjrv, Commented Oct 4, 2015 at 21:30
you can add a prefix to depends to ensure that alpha order is the correct order. — dandavis
– dandavis, Commented Oct 4, 2015 at 21:31
well I have dependencies, so I don't think I should do this. I would have to come up with a naming convention to assure the order. For example if obj2 needs obj0 and obj1, I would need to make sure they were loaded first. — cade galt
– cade galt, Commented Oct 4, 2015 at 21:32

Ignacio Vazquez-Abrams · Accepted Answer · 2015-10-04 22:29:45Z

2

First, create a file that describes your dependencies.

obj0 obj2
obj1 obj2

Now tsort(1) can give you an ordering.

$ tsort dep.txt
obj0
obj1
obj2

Now you can read each line in turn and output the files in the correct order.

{
  while read obj
  do
    cat "object.$obj.js"
  done < <(tsort dep.txt)
} > all.js

answered Oct 4, 2015 at 22:29

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2 Comments

Here is a nice explanation of tort - viget.com/extend/dependency-sorting-in-ruby-with-tsort - It uses a dependency hash. Can i write dep. txt in JSON ? Or is it just space separated like in your example.

@cadegalt: As the man page explains, the input file is whitespace-delimited.