gnupg/g10/textfilter.c

144 lines
3.0 KiB
C

/* textfilter.c
* Copyright (C) 1998 Free Software Foundation, Inc.
*
* This file is part of GNUPG.
*
* GNUPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GNUPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "errors.h"
#include "iobuf.h"
#include "memory.h"
#include "util.h"
#include "filter.h"
static int
read_line( byte *buf, size_t *r_buflen, IOBUF a )
{
int c;
int rc = 0;
byte *p;
size_t buflen;
int no_lf=0;
size_t n;
buflen = *r_buflen;
assert(buflen >= 20 );
buflen -= 3; /* leave some room for CR,LF and one extra */
for(c=0, n=0; n < buflen && (c=iobuf_get(a)) != -1 && c != '\n'; )
buf[n++] = c;
buf[n] = 0;
if( c == -1 ) {
rc = -1;
if( !n || buf[n-1] != '\n' )
no_lf = 1;
}
else if( c != '\n' ) {
IOBUF b = iobuf_temp();
while( (c=iobuf_get(a)) != -1 && c != '\n' ) {
iobuf_put(b,c);
if( c != ' ' && c != '\t' && c != '\r' )
break;
}
if( c == '\n' ) { /* okay we can skip the rest of the line */
iobuf_close(b);
}
else {
iobuf_unget_and_close_temp(a,b);
no_lf = 1;
}
}
if( !no_lf ) {
/* append CR,LF after removing trailing wspaces */
for(p=buf+n-1; n; n--, p-- ) {
assert( *p != '\n' );
if( *p != ' ' && *p != '\t' && *p != '\r' ) {
p[1] = '\r';
p[2] = '\n';
n += 2;
break;
}
}
if( !n ) {
buf[0] = '\r';
buf[1] = '\n';
n = 2;
}
}
*r_buflen = n;
return rc;
}
/****************
* The filter is used to make canonical text: Lines are terminated by
* CR, LF, trailing white spaces are removed.
*/
int
text_filter( void *opaque, int control,
IOBUF a, byte *buf, size_t *ret_len)
{
size_t size = *ret_len;
text_filter_context_t *tfx = opaque;
int rc=0;
size_t len, n, nn;
if( control == IOBUFCTRL_UNDERFLOW ) {
assert( size > 30 );
len = 0;
while( !rc && len < size ) {
if( tfx->idx < tfx->len ) { /* flush the last buffer */
n = tfx->len;
for(nn=tfx->idx; len < size && nn < n ; nn++ )
buf[len++] = tfx->buf[nn];
tfx->idx = nn;
continue;
}
if( tfx->eof ) {
rc = -1;
continue;
}
n = DIM(tfx->buf);
tfx->idx = 0;
if( read_line( tfx->buf, &n, a ) == -1 )
tfx->eof = 1;
tfx->len = n;
}
*ret_len = len;
}
else if( control == IOBUFCTRL_DESC )
*(char**)buf = "text_filter";
return rc;
}