From elim@research.att.com Tue Oct 5 15:21:28 1999 Received: from mail-blue.research.att.com (mail-blue.research.att.com [135.207.30.102]) by pell.portland.or.us (8.8.5/8.8.5) with ESMTP id PAA25675 for ; Tue, 5 Oct 1999 15:21:27 -0700 Received: from alliance.research.att.com (alliance.research.att.com [135.207.26.26]) by mail-blue.research.att.com (Postfix) with ESMTP id 142264CE0F for ; Tue, 5 Oct 1999 18:20:37 -0400 (EDT) Received: from elim-sgi.research.att.com (elim-sgi.research.att.com [135.207.20.85]) by alliance.research.att.com (8.8.7/8.8.7) with ESMTP id SAA21301 for ; Tue, 5 Oct 1999 18:20:36 -0400 (EDT) From: Edwin Lim Received: (from elim@localhost) by elim-sgi.research.att.com (980427.SGI.8.8.8/8.8.5) id SAA70628 for ; Tue, 5 Oct 1999 18:20:35 -0400 (EDT) Date: Tue, 5 Oct 1999 18:20:35 -0400 (EDT) Message-Id: <199910052220.SAA70628@elim-sgi.research.att.com> To: "David Parsons" Subject: Re: Magicfilter X-Status: X-Keywords: X-UID: 837 Status: O > I have a spiffy little ndialog setup box that, alas, doesn't work all > the time -- I've been working on making it easier to plug ndialog > into a system without having to do much compiling, and the bulk of > that is scribbling around the peripherals of magicfilter (and cursing > a blue streak about some of the more charming misfeatures in lpd.) I just have a couple of stuffs that I ran up against when I tried to use magicfilter. I am not sure if the current code has addressed these points but here they are anyway: 1) The "optimistic troff magic" was invoked accidentally on some non-troff input. E.g., the output of a "find . -print" is normally . ./foo ./foo/bar The leading '.' triggers the the troff (in)magic :-). My solution is to comment that line out, although I think using file(1) might be a good idea (that will mean a complete rewrite of the code...). 2) The final "Default entry" comes too soon... I mean there are some really nasty binaries data that will fail all preceeding checks. For example, if I "tail /bin/ls", the filter will assume that it is printable ascii and tries to send it to the printer. For this, I wrote a simple program (/print/bin/textonly) that will scan stdin and passthrough printable data and do some hex dump of non-printable data. I put it right at the end of the filter like: # Default entry -- for normal (text) files. MUST BE LAST. default pipe /print/bin/textonly | /usr/common/bin/enscript -B -p- I have included the code below, feel free to ignore it or do whatever you want to it. Cheers, e. -- Help Desk Person Edwin Lim 973-360-7058 fp c254 Your fault -- core dumped Some snack -- http://www.ftech.net/~honeyg/progstone/index.html Devolution -- http://www.improbable.com/ig/ig-top.html /*********************************************************************** * textonly.c * * Simple program that makes sure that stdin is printable stuff. * If not, output simple hex dump, otherwise copy to stdout. * Meant to be a final sanity check pipe printer filter. * * Ed Lim Fri Sep 24 00:56:56 EDT 1999 * ***********************************************************************/ #include #include /*********************************************************************** * Prototypes ***********************************************************************/ int scan_input(unsigned char *, int); void hex_dump(unsigned char *, int, int); void shove_out(unsigned char *, int); /* will check this many bytes each iteration to determine printability: */ #define CHUNK_SIZE 512 /* can't be sent to printer */ char nonprint[256] = { 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, }; /* non-visible , for the hexdump part */ char nonscreen[256] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, }; /*********************************************************************** * MAIN ***********************************************************************/ int main() { int insize = 0; unsigned char inbuf[CHUNK_SIZE]; int total_read = 0; for ( ; ; ) { insize = read(0, inbuf, CHUNK_SIZE); if ( insize <= 0 ) { break; } else if ( scan_input(inbuf, insize) ) { hex_dump(inbuf, insize, total_read); break; } else { shove_out(inbuf, insize); } total_read += insize; } return 0; } /*********************************************************************** * scan_input * * Scan input buffer for illegal characters. * * Returns: * Number of illegal characters found. * ************************************************************************/ int scan_input(unsigned char *inbuf, int insize) { int bad_chars = 0; int i; for ( i = 0 ; i < insize ; i++ ) { bad_chars += nonprint[inbuf[i]]; } return bad_chars; } /*********************************************************************** * hex_dump * * This will do some sort of hex dump. * ***********************************************************************/ void hex_dump(unsigned char *stuff_to_dump, int size, int fake_offset) { int line_loc, i, this_line_size; int dumped = 0; int temp; /* some header stuff */ printf ("\n%s\n%s\n\n", "Non-printable characters encountered. Printing aborted.", "Offending characters are prepended by '!'."); while ( dumped < size ) { /* offset number */ line_loc = printf("%010x:", fake_offset + dumped); /* how many characters for this line? */ this_line_size = (size - dumped) < 16 ? (size - dumped) : 16; /* hex part */ for (i = 0 ; i < this_line_size ; i++) { line_loc += printf("%c%02x", nonprint[stuff_to_dump[dumped + i]] ? '!' : ' ', stuff_to_dump[dumped + i]); } /* ascii part */ for (i = line_loc ; i < 62 ; i++) printf(" "); for (i = 0 ; i < this_line_size ; i++) { printf("%c", nonscreen[stuff_to_dump[dumped + i]] ? '.' : stuff_to_dump[dumped + i]); } printf("\n"); dumped += this_line_size; } return; } /*********************************************************************** * shove_out * * Output stuff. * ***********************************************************************/ void shove_out(unsigned char *stuff_to_shove, int size) { int this_shovel, shoved = 0; unsigned char *ptr = stuff_to_shove; while ( shoved < size ) { this_shovel = write(1, ptr, (size - shoved)); if ( this_shovel < 0 ) exit(-1); shoved += this_shovel; ptr += this_shovel; } return; } /* * vim: tabstop=4 shiftwidth=4 autoindent expandtab smartindent nohlsearch */