Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Adam is pointing in exactly the right direction. </p> <p>If you want to find out how to <strong>sense almost any file</strong>, look at the database behind the <code>file</code> command on a UNIX, Linux, or Mac OS X machine. </p> <p><code>file</code> uses a database of “magic numbers” — those initial bytes Adam listed — to sense a file's type. <code>man file</code> will tell you where to find the database on your machine, e.g. <code>/usr/share/file/magic</code>. <code>man magic</code> will tell you its <a href="http://linux.die.net/man/5/magic" rel="noreferrer">format</a>. </p> <p>You can either write your own detection code based on what you see in the database, use pre-packaged libraries (e.g. <a href="http://hupp.org/adam/hg/python-magic" rel="noreferrer">python-magic</a>), or — if you're <em>really</em> adventurous — implement a .NET version of <code>libmagic</code>. I couldn't find one, and hope another member can point one out. </p> <p>In case you don't have a UNIX machine handy, the database looks like this:</p> <pre> # PNG [Portable Network Graphics, or "PNG's Not GIF"] images # (Greg Roelofs, newt@uchicago.edu) # (Albert Cahalan, acahalan@cs.uml.edu) # # 137 P N G \r \n ^Z \n [4-byte length] H E A D [HEAD data] [HEAD crc] ... # 0 string \x89PNG PNG image data, >4 belong !0x0d0a1a0a CORRUPTED, >4 belong 0x0d0a1a0a >>16 belong x %ld x >>20 belong x %ld, >>24 byte x %d-bit >>25 byte 0 grayscale, >>25 byte 2 \b/color RGB, >>25 byte 3 colormap, >>25 byte 4 gray+alpha, >>25 byte 6 \b/color RGBA, #>>26 byte 0 deflate/32K, >>28 byte 0 non-interlaced >>28 byte 1 interlaced 1 string PNG PNG image data, CORRUPTED # GIF 0 string GIF8 GIF image data >4 string 7a \b, version 8%s, >4 string 9a \b, version 8%s, >6 leshort >0 %hd x >8 leshort >0 %hd #>10 byte &0x80 color mapped, #>10 byte&0x07 =0x00 2 colors #>10 byte&0x07 =0x01 4 colors #>10 byte&0x07 =0x02 8 colors #>10 byte&0x07 =0x03 16 colors #>10 byte&0x07 =0x04 32 colors #>10 byte&0x07 =0x05 64 colors #>10 byte&0x07 =0x06 128 colors #>10 byte&0x07 =0x07 256 colors </pre> <p>Good luck!</p>
    singulars
    1. This table or related slice is empty.
    1. PODetermine file type of an image
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USGarth Kidd
    1. USGarth Kidd
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload