1/* Copyright (C) 1999-2001, 2003, 2011 Bruno Haible.
2   This file is not part of the GNU LIBICONV Library.
3   This file is put into the public domain.  */
4
5#include "iconv_string.h"
6#include <iconv.h>
7#include <errno.h>
8#include <stdlib.h>
9#include <string.h>
10
11#define tmpbufsize 4096
12
13int iconv_string (const char* tocode, const char* fromcode,
14                  const char* start, const char* end,
15                  char** resultp, size_t* lengthp)
16{
17  iconv_t cd = iconv_open(tocode,fromcode);
18  size_t length;
19  char* result;
20  if (cd == (iconv_t)(-1)) {
21    if (errno != EINVAL)
22      return -1;
23    /* Unsupported fromcode or tocode. Check whether the caller requested
24       autodetection. */
25    if (!strcmp(fromcode,"autodetect_utf8")) {
26      int ret;
27      /* Try UTF-8 first. There are very few ISO-8859-1 inputs that would
28         be valid UTF-8, but many UTF-8 inputs are valid ISO-8859-1. */
29      ret = iconv_string(tocode,"UTF-8",start,end,resultp,lengthp);
30      if (!(ret < 0 && errno == EILSEQ))
31        return ret;
32      ret = iconv_string(tocode,"ISO-8859-1",start,end,resultp,lengthp);
33      return ret;
34    }
35    if (!strcmp(fromcode,"autodetect_jp")) {
36      int ret;
37      /* Try 7-bit encoding first. If the input contains bytes >= 0x80,
38         it will fail. */
39      ret = iconv_string(tocode,"ISO-2022-JP-2",start,end,resultp,lengthp);
40      if (!(ret < 0 && errno == EILSEQ))
41        return ret;
42      /* Try EUC-JP next. Short SHIFT_JIS inputs may come out wrong. This
43         is unavoidable. People will condemn SHIFT_JIS.
44         If we tried SHIFT_JIS first, then some short EUC-JP inputs would
45         come out wrong, and people would condemn EUC-JP and Unix, which
46         would not be good. */
47      ret = iconv_string(tocode,"EUC-JP",start,end,resultp,lengthp);
48      if (!(ret < 0 && errno == EILSEQ))
49        return ret;
50      /* Finally try SHIFT_JIS. */
51      ret = iconv_string(tocode,"SHIFT_JIS",start,end,resultp,lengthp);
52      return ret;
53    }
54    if (!strcmp(fromcode,"autodetect_kr")) {
55      int ret;
56      /* Try 7-bit encoding first. If the input contains bytes >= 0x80,
57         it will fail. */
58      ret = iconv_string(tocode,"ISO-2022-KR",start,end,resultp,lengthp);
59      if (!(ret < 0 && errno == EILSEQ))
60        return ret;
61      /* Finally try EUC-KR. */
62      ret = iconv_string(tocode,"EUC-KR",start,end,resultp,lengthp);
63      return ret;
64    }
65    errno = EINVAL;
66    return -1;
67  }
68  /* Determine the length we need. */
69  {
70    size_t count = 0;
71    char tmpbuf[tmpbufsize];
72    const char* inptr = start;
73    size_t insize = end-start;
74    while (insize > 0) {
75      char* outptr = tmpbuf;
76      size_t outsize = tmpbufsize;
77      size_t res = iconv(cd,&inptr,&insize,&outptr,&outsize);
78      if (res == (size_t)(-1) && errno != E2BIG) {
79        int saved_errno = (errno == EINVAL ? EILSEQ : errno);
80        iconv_close(cd);
81        errno = saved_errno;
82        return -1;
83      }
84      count += outptr-tmpbuf;
85    }
86    {
87      char* outptr = tmpbuf;
88      size_t outsize = tmpbufsize;
89      size_t res = iconv(cd,NULL,NULL,&outptr,&outsize);
90      if (res == (size_t)(-1)) {
91        int saved_errno = errno;
92        iconv_close(cd);
93        errno = saved_errno;
94        return -1;
95      }
96      count += outptr-tmpbuf;
97    }
98    length = count;
99  }
100  if (lengthp != NULL)
101    *lengthp = length;
102  if (resultp == NULL) {
103    iconv_close(cd);
104    return 0;
105  }
106  result = (*resultp == NULL ? malloc(length) : realloc(*resultp,length));
107  *resultp = result;
108  if (length == 0) {
109    iconv_close(cd);
110    return 0;
111  }
112  if (result == NULL) {
113    iconv_close(cd);
114    errno = ENOMEM;
115    return -1;
116  }
117  iconv(cd,NULL,NULL,NULL,NULL); /* return to the initial state */
118  /* Do the conversion for real. */
119  {
120    const char* inptr = start;
121    size_t insize = end-start;
122    char* outptr = result;
123    size_t outsize = length;
124    while (insize > 0) {
125      size_t res = iconv(cd,&inptr,&insize,&outptr,&outsize);
126      if (res == (size_t)(-1)) {
127        if (errno == EINVAL)
128          break;
129        else {
130          int saved_errno = errno;
131          iconv_close(cd);
132          errno = saved_errno;
133          return -1;
134        }
135      }
136    }
137    {
138      size_t res = iconv(cd,NULL,NULL,&outptr,&outsize);
139      if (res == (size_t)(-1)) {
140        int saved_errno = errno;
141        iconv_close(cd);
142        errno = saved_errno;
143        return -1;
144      }
145    }
146    if (outsize != 0) abort();
147  }
148  iconv_close(cd);
149  return 0;
150}
151