# nameme 
> na·me·me | **\\na-me-me\\** </br> 
> **1.** A simple utility to find the real filetype of a file based on its magic number and, optionally, rename it. 

## Usage 
`nameme` is a CLI program that given a path prints the type of the contents the path based 
on the magic number of the content itself. For example, in a folder such as the following 
``` bash
.
├── a
├── Cats
│   ├── 1.jpg  	(* <- Actually a BMP image *)
│   ├── 2.jpg  
│   ├── 3.jpg
│   └── 4.jpg
└─ Dogs
   ├── 1.jpg
   ├── 2.jpg
   ├── 3.jpg 	(* <- Actually a GIF *)
   └── 4.jpg
```
invoking `nameme .` would print 
``` shell
$ nameme . 
Format	 	Results	Erroneous
BMP		1		1
GIF		1		1
JPG		7		0
```

To see which files are misnamed, you can use `nameme --verbose`: 
``` shell
$ nameme --verbose . 
Format		Results	Erroneous
BMP		1		1
	./Cats/1.jpg
GIF		1		1
	./Dogs/3.jpg
JPG		7		0
	./Cats/3.jpg
	./Cats/5.jpg
	./Cats/2.jpg
	./Cats/4.jpg
	./Dogs/1.jpg
	./Dogs/2.jpg
	./Dogs/4.jpg
```

The other use of `nameme` is that of automatically renaming files according to
their magic number[^1]:
``` shell
$ tree .
.
├── Cats
│   ├── 1.jpg
│   ├── 2.jpg
│   ├── 3.jpg
│   ├── 4.jpg
│   └── 5.jpg
└── Dogs
    ├── 1.jpg
    ├── 2.jpg
    ├── 3.jpg
    └── 4.jpg
$ nameme --rename --auto .
$ tree .
.
├── Cats
│   ├── 1.bmp
│   ├── 2.jpg
│   ├── 3.jpg
│   ├── 4.jpg
│   └── 5.jpg
└── Dogs
    ├── 1.jpg
    ├── 2.jpg
    ├── 3.gif
    └── 4.jpg
```

If you prefer to be asked whether or not a certain file should be renamed,
removing the `--auto` flag from the invocation in the previous example will make `nameme`
ask you for each potential rename:
``` shell 
$ nameme --rename .
rename ./Cats/1.jpg -> ./Cats/1.bmp? [Y/n] y
rename ./Dogs/3.jpg -> ./Dogs/3.gif? [Y/n] y
```

## Todo
Items marked as complete in this list can still be improved.

 - [x] Each header pattern may correspond to multiple extensions. A user should
   have the possiblity to choose the desired extension among those available
   when renaming a file. 

 - [ ] A user should be able to decide whether the header is matched greedily
   (that is, the longest match is taken, as it is now) or lazily (that is, the
   shortest match is taken). 

 - [x] When invoked on a large directory, `nameme` can get pretty slow. Figure
   out what's the problem.

 - [ ] `file` is able to figure out filetypes of some text files (e.g. json).
   Figure out if it makes sense to implement something similar here, and how. 


## Credits 
This library and application are based on [GCK's File Signatures
Table](https://www.garykessler.net/library/file_sigs.html), distributed under
MIT license.
[^1]: A single header pattern might correspond to multiple possible extensions.
  Ideally, the user should be able to choose which of the available extension
  to choose, but this can get tedious really fast for large files.