nsayer@uop.edu (Nick Sayer) (10/24/90)
It is my understanding that GIF files are identified as such by the first three letters of the file being GIF, and that the version of GIF file is identified by the next 3. With that in mind, I came up with this addition to /etc/magic: 0 string GIF GIF image >3 byte&0x7f x (version %c >4 byte&0x7f x %c >5 byte&0x7f x %c) Not only is this a little on the cumbersome side, it results in: foo.gif GIF image (version 8 7 a) What I REALLY want is: 0 string GIF GIF image >3 string xxx (version %s) but that doesn't work, obviously. Any ideas? -- Nick Sayer | "Disclaimer? I don't think so! | RIP: Mel Blanc mrapple@quack.sac.ca.us | Homey don't play dat." | 1908-1989 N6QQQ [44.2.1.17] | | May he never 209-952-5347 (Telebit) | --Homey the Clown | be silenced.
matthew@sunpix.east.sun.com (Matthew Stier - Sun Visualization Products) (10/25/90)
In article <2725be7d.55aa@uop.uop.edu> nsayer@uop.edu (Nick Sayer) writes: >What I REALLY want is: > >0 string GIF GIF image >>3 string xxx (version %s) > >but that doesn't work, obviously. Any ideas? > To quote the man page: For string values, the byte string from the file must match the specified byte string; the byte string from the file which is matched is the same length as the specified byte string. In other words, your 'ideal' /etc/magic' entry is looking for the character string 'xxx'. To fix this problem, one would have to change 'file(1)' to have some wildcard pattern for strings. I get around the problem with these lines: 0 string GIF GIF image >3 string 87a (version 87a) >3 string 89a (version 89a) These are the only two version numbers currently authorized by Compuserve. -- Matthew Lee Stier (mstier@east.Sun.COM) | Sun Microsystems --- RTP, NC 27709-3447 | "Wisconsin Escapee" uucp: sun!mstier or mcnc!rti!sunpix!matthew | phone: (919) 469-8300 fax: (919) 460-8355 |
pim@cti-software.nl (Pim Zandbergen) (11/01/90)
matthew@sunpix.east.sun.com (Matthew Stier - Sun Visualization Products) writes: 0 string GIF GIF image >3 string 87a (version 87a) >3 string 89a (version 89a) This entry also lists the resolution of your GIF image: (at least when your CPU has the same byte order as the 80386) 0x0 string GIF GIF picture >0x3 string 87a - version %s >0x3 string 89a - version %s >0x6 short >0 (%d >0x8 short >0 x %d) Now if I only could list the number of colours! -- Pim Zandbergen domain : pim@cti-software.nl CTI Software BV uucp : uunet!mcsun!hp4nl!ctisbv!pim Laan Copes van Cattenburch 70 phone : +31 70 3542302 2585 GD The Hague, The Netherlands fax : +31 70 3512837