Added a 'magic' file to identify index files with file command

README.md

@@ -7,6 +7,8 @@ No more waiting when the end of a 10 GiB gzip is needed!
 
 See [`Installation`](https://github.com/circulosmeos/gztool#installation) for Ubuntu, the [Release page](https://github.com/circulosmeos/gztool/releases) for executables for your platform, and [`Compilation`](https://github.com/circulosmeos/gztool#compilation) in case you want to compile the tool.
 
+Also, a *`magic`* file to correctly identify `gztool`'s index files with linux `file` command is provided: you can append it (or overwrite your empty) `/etc/magic` file or append/copy it to your home directory as `~/.magic` (note the point prepending the name).
+
 Considerations
 ==============
 
@@ -86,7 +88,7 @@ Copy gztool.c to the directory where you compiled zlib, and do:
 Usage
 =====
 
-      gztool (v0.11.1)
+      gztool (v0.11.2)
       GZIP files indexer, compressor and data retriever.
       Create small indexes for gzipped files and use them
       for quick and random positioned data extraction.
@@ -313,6 +315,8 @@ With 64 bit long numbers, the index could potentially manage files up to 2^64 =
 
 Regarding line number counting (`-[xX]`), note that gztool's index counts last line in uncompressed data even if the last char isn't a newline char - whilst `wc` command will not count it in this case!. Nonetheless, line counting when extracting data with `-[bLtT]` does follow `wc` convention - this is in order to not obtain different (+/-1) results reading `gztool` output info and `wc` counts.
 
+A *`magic`* file to correctly identify `gztool`'s index files with linux `file` command is provided: you can append it (or overwrite your empty) `/etc/magic` file or append/copy it to your home directory as `~/.magic` (note the point prepending the name).
+
 Other tools which try to provide random access to gzipped files
 ===============================================================
 
@@ -354,7 +358,7 @@ Other interesting links
 Version
 =======
 
-This version is **v0.11.1**.
+This version is **v0.11.2**.
 
 Please, read the *Disclaimer*. This is still a beta release. In case of any errors, please open an [issue](https://github.com/circulosmeos/gztool/issues).
 

magic

@@ -0,0 +1,5 @@
+# Magic local data for file(1) command.
+# Insert here your local magic data. Format is described in magic(5).
+
+0       string  \0\0\0\0\0\0\0\0gzipindx        GZIP index file (v0), usable with gztool
+0       string  \0\0\0\0\0\0\0\0gzipindX        GZIP index file (v1) with line info, usable with gztool