1 /* Copyright 1996,1997,1999,2001-2003,2008,2009,2021 Alain Knaff.
2 * This file is part of mtools.
3 *
4 * Mtools is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * Mtools is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with Mtools. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include "sysincludes.h"
19 #include "msdos.h"
20 #include "mtools.h"
21 #include "codepage.h"
22
23 #define U2D_BUFSIZE 4096
24
25 typedef struct Filter_t {
26 struct Stream_t head;
27
28 char buffer[U2D_BUFSIZE];
29
30 size_t readBytes; /* how many bytes read into buffer */
31 size_t bufPos; /* position in buffer */
32
33 bool pendingNl;
34 bool eof;
35 } Filter_t;
36
37 /* Add CR before NL, and 0x1a at end of file */
read_filter(Stream_t * Stream,char * output,size_t len)38 static ssize_t read_filter(Stream_t *Stream, char *output, size_t len)
39 {
40 DeclareThis(Filter_t);
41 size_t i;
42
43 if(This->eof)
44 return 0;
45
46 for(i=0; i < len && !This->eof; i++) {
47 char c;
48 if(This->pendingNl) {
49 c='\n';
50 This->pendingNl=false;
51 } else {
52 if(This->bufPos == This->readBytes) {
53 ssize_t ret = READS(This->head.Next,
54 This->buffer,
55 U2D_BUFSIZE);
56 if(ret < 0) {
57 /* an error */
58 /* If we already have read some data,
59 * first return count of that data
60 * before returning error */
61 if(i == 0)
62 return -1;
63 else
64 break;
65 }
66 This->readBytes = (size_t) ret;
67 This->bufPos = 0;
68 }
69
70 if(This->bufPos == This->readBytes) {
71 /* Still at end of buffer, must be end
72 of file */
73 c='\032';
74 This->eof=true;
75 } else {
76 c = This->buffer[This->bufPos++];
77 if(c == '\n') {
78 This->pendingNl=true;
79 c = '\r';
80 }
81 }
82 }
83 output[i]=c;
84 }
85
86 return (ssize_t) i;
87 }
88
89 static Class_t FilterClass = {
90 read_filter,
91 0,
92 0,
93 0,
94 0, /* flush */
95 0,
96 0, /* set geometry */
97 get_data_pass_through,
98 0,
99 0, /* get_dosconvert */
100 0 /* discard */
101 };
102
open_unix2dos(Stream_t * Next,int convertCharset UNUSEDP)103 Stream_t *open_unix2dos(Stream_t *Next, int convertCharset UNUSEDP)
104 {
105 Filter_t *This;
106
107 This = New(Filter_t);
108 if (!This)
109 return NULL;
110 init_head(&This->head, &FilterClass, Next);
111
112 This->readBytes = This->bufPos = 0;
113 This->pendingNl = false;
114 This->eof = false;
115
116 return &This->head;
117 }
118