Re: searching non plain text files

On Sun, 2018-12-16 at 14:33 -0500, Tedd Sperling wrote: > > On Dec 14, 2018, at 11:19 PM, Jeffry Killen <jekillen@prodigy.net> wrote: > > > > > > Can anyone point me to instruction/advice about > > opening and reading files that are not plain text: > > Jeffry: > > I don’t know if this will help you, but most “honest” files have a header that > states what it is. > > Try using a hex-editor app and observing the first 10 characters in their > headers (i.e., start of the file). For example, a PDF file will state ‘PDF’, a > jpg will state ’JFIF’, a rtf file will state ‘rtf’, a zip file will state > ‘PK”, a png will state ‘PNG”, and so on. > > From that observation, you might try working with bin2hex or dechex and other > such bin/hex functions PHP provides to check what the file type is in the > header and what it reports itself to be in the extension. > > Additionally, you can always Google it. > Just to confuse the issue, both zip files and odt (Open Document) files have the 'PK' header id. Looking around for some other formats, I found that most tgz files (tar, gzipped) have 'vV' followed by the file name (but not all of them!). So Jeffry will have to do some sort of a secondary test to be sure. John ============================= > Cheers, > > Tedd > > _______________ > tedd sperling > tedd@sperling.com > > > > >