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/*
* From owner-mgetty Wed Jun 28 02:08:30 1995
* Return-Path: <owner-mgetty>
* Received: by greenie.muc.de (/\==/\ Smail3.1.24.1 #24.2)
* id <m0sQkgA-0001nCC@greenie.muc.de>; Wed, 28 Jun 95 02:08 MEST
* Return-Path: <l-mgetty-owner@muc.de>
* Received: by greenie.muc.de (/\==/\ Smail3.1.24.1 #24.2)
* id <m0sQkg6-0002jPC@greenie.muc.de>; Wed, 28 Jun 95 02:08 MEST
* Received: from greenie.muc.de ([193.174.4.62]) by colin.muc.de with SMTP id <25543-2>; Wed, 28 Jun 1995 02:08:14 +0200
* Received: by greenie.muc.de (/\==/\ Smail3.1.24.1 #24.2)
* id <m0sQkXo-0001nCC@greenie.muc.de>; Wed, 28 Jun 95 01:59 MEST
* Received: from GATEWAY by greenie.muc.de with netnews
* for mgetty@muc.de (mgetty@muc.de)
* To: mgetty@muc.de
* Date: Sat, 24 Jun 1995 21:26:42 +0200
* From: fdc@cliwe.ping.de (Frank D. Cringle)
* Message-ID: <vt68lv7cb1.fsf_-_@cliwe.ping.de>
* Organization: calls for speculation
* References: <m0sNnpJ-0001v0C@greenie.muc.de>
* Subject: Save the forests (was: Conversion ascii->g3)
* Status: RO
*
* gert@greenie.muc.de (Gert Doering) writes:
* >Erlend Schei wrote:
* >> Any recommendations (perhaps som script-gurus who know how to make
* >> gslp skip the white stuff at the end of the last page)?
* >
* >I'd like to see that too. I don't think it's easy, you'll have to hack the
* >dfaxhigh (or faxg3) driver, I think.
*
* Here is a nasty little hack that will chop the end off a g3 file. It
* is nasty 'cos it only works for single-page 1d-encoded files with
* msbfirst bit order. But that is what mgetty uses at present, so what
* the hell.
*
* It is rather cool in the way that it decides what to chop. All
* identical lines at the end of the page are candidates and any more
* than 10 (by default) are discarded. It does not matter whether they
* are white, black or striped.
*
* I leave it to a competent shell programmer to integrate it into the
* faxspool script.
*
* ----------------------------------------------------------------
*/
/* g3hack.c - hack identical lines off the end of a fax
*
* This program is in the public domain. If it does not work or
* causes you any sort of grief, blame the public, not me.
*
* fdc@cliwe.ping.de, 1995-06-24
*
* $Id: g3hack.c,v 1.2 2006/06/14 10:33:14 gert Exp $
*
* $Log: g3hack.c,v $
* Revision 1.2 2006/06/14 10:33:14 gert
* add <memory.h> to silence compiler warnings
* add ibits=0 to silence compiler warning
* (the code was correct, but the compiler didn't see this...)
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
extern int getopt();
extern char *optarg;
extern int optind, opterr;
char *usage = "usage: %s <-n count> <-h size> -o <outputfile>\n\n\
Copy a g3-(1d)-fax file from stdin to stdout and delete any\n\
more than `count' identical trailing lines (default 10).\n\
Optionally skip `size'-byte header.\n\
Optionally named outputfile (else stdout).\n";
#define nxtbit() ((imask>>=1) ? ((ibits&imask)!=0) : \
((ibits=getchar()) == EOF) ? -1 : \
(((imask=0x80)&ibits)!=0))
#define putbit(b) \
do { \
if (b) \
obits |= omask; \
if ((omask >>= 1) == 0) { \
this->line[this->length>>3] = obits; \
omask = 0x80; \
obits = 0; \
} \
this->length++; \
if (this->length >= BUFSIZ<<3) { \
fputs("g3hack: unreasonably long line\n", stderr); \
exit(1); \
} \
} while (0)
static void
copy(int nlines)
{
int ibits = 0, imask = 0; /* input bits and mask */
int obits = 0; /* output bits */
int omask = 0x80; /* output mask */
int zeros = 0; /* number of consecutive zero bits */
int thisempty = 1; /* empty line (so far) */
int empties = 0; /* number of consecutive EOLs */
int identcount = 0; /* number of consecutive identical lines */
struct {
char line[BUFSIZ];
int length;
} lines[2], *prev, *this, *temp;
this = &lines[0];
prev = &lines[1];
this->length = prev->length = 0;
while (!ferror(stdout)) {
int bit = nxtbit();
if (bit == -1)
break; /* end of file */
putbit(bit);
if (bit == 0) {
zeros++;
continue;
}
if (zeros < 11) { /* not eol and not empty */
zeros = 0;
thisempty = 0;
for ( ; empties; empties--)
fwrite("\0\1", 1, 2, stdout);
continue;
}
/* at end of line */
zeros = 0;
omask = 0x80;
obits = 0;
if (thisempty) {
empties++;
if (empties >= 6)
break;
this->length = 0;
continue;
}
thisempty = 1;
/* at end of non-empty line */
identcount++;
this->length = (this->length+7)&~7;
this->line[(this->length-1)>>3] = 1; /* byte-align the eol */
if (this->length == prev->length &&
memcmp(this->line, prev->line, this->length>>3) == 0) {
this->length = 0;
continue;
}
/* at end of non-matching line */
for ( ; identcount; identcount--)
fwrite(prev->line, 1, prev->length>>3, stdout);
temp = prev;
prev = this;
this = temp;
this->length = 0;
}
if (identcount > nlines)
identcount = nlines;
for ( ; !ferror(stdout) && identcount; identcount--)
fwrite(prev->line, 1, prev->length>>3, stdout);
for ( ; !ferror(stdout) && empties; empties--)
fwrite("\0\1", 1, 2, stdout);
if (ferror(stdout)) {
fputs("write error\n", stderr);
exit(1);
}
}
int
main(int argc, char **argv)
{
int c;
int header = 0;
int nlines = 10;
opterr = 0;
while ((c = getopt(argc, argv, "h:n:o:")) != EOF)
switch (c) {
case 'h':
header = atoi(optarg);
break;
case 'n':
nlines = atoi(optarg);
break;
case 'o':
if (freopen(optarg, "w", stdout) == NULL) {
perror(optarg);
exit(1);
}
break;
case '?':
fprintf(stderr, usage, argv[0]);
exit(1);
}
while (header--)
putchar(getchar());
copy(nlines);
exit(0);
}
/*
* --
* Frank Cringle | fdc@cliwe.ping.de
* voice + fax | +49 2304 467101
*/
|
