Convert from UTF-8 to ISO8859-15 in C++
I would like to do a conversion from UTF-8 to ISO 8859-15 in C/C++, without including an additional library.
How can I achieve this?
I have found the following piece of code that works for ISO 8859-1 but I'm not sure about how to handle the differences between ISO 8859-15 and ISO 8859-1 (https://en.wikipedia.org/wiki/ISO/IEC_8859-15) :
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
if (codepoint <= 255) {
out.append(1, static_cast<char>(codepoint));
}
else {
out.append("?");
}
}
}
return out;
}
c++ string encoding utf-8 iso-8859-15
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
add a comment |
I would like to do a conversion from UTF-8 to ISO 8859-15 in C/C++, without including an additional library.
How can I achieve this?
I have found the following piece of code that works for ISO 8859-1 but I'm not sure about how to handle the differences between ISO 8859-15 and ISO 8859-1 (https://en.wikipedia.org/wiki/ISO/IEC_8859-15) :
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
if (codepoint <= 255) {
out.append(1, static_cast<char>(codepoint));
}
else {
out.append("?");
}
}
}
return out;
}
c++ string encoding utf-8 iso-8859-15
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
1
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58
add a comment |
I would like to do a conversion from UTF-8 to ISO 8859-15 in C/C++, without including an additional library.
How can I achieve this?
I have found the following piece of code that works for ISO 8859-1 but I'm not sure about how to handle the differences between ISO 8859-15 and ISO 8859-1 (https://en.wikipedia.org/wiki/ISO/IEC_8859-15) :
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
if (codepoint <= 255) {
out.append(1, static_cast<char>(codepoint));
}
else {
out.append("?");
}
}
}
return out;
}
c++ string encoding utf-8 iso-8859-15
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
I would like to do a conversion from UTF-8 to ISO 8859-15 in C/C++, without including an additional library.
How can I achieve this?
I have found the following piece of code that works for ISO 8859-1 but I'm not sure about how to handle the differences between ISO 8859-15 and ISO 8859-1 (https://en.wikipedia.org/wiki/ISO/IEC_8859-15) :
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
if (codepoint <= 255) {
out.append(1, static_cast<char>(codepoint));
}
else {
out.append("?");
}
}
}
return out;
}
c++ string encoding utf-8 iso-8859-15
c++ string encoding utf-8 iso-8859-15
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
asked Nov 12 '18 at 20:14
KamchatkaKamchatka
2,18122761
2,18122761
1
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58
add a comment |
1
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58
1
1
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58
add a comment |
1 Answer
1
active
oldest
votes
I like this code. It's surprisingly short. Most of the code just deals with decoding multi-byte sequences into codepoints. Once a codepoint has been decoded, the conversion to ISO-8859-1 is very simple:
- If it's less or equal 255, it's also a valid ISO-8859-1 character:
out.append(1, static_cast<char>(codepoint));
- If not, it cannot be represented in ISO-8859-1 and is replaced with a question mark:
out.append("?");
So to make it work for ISO-8859-15, more code is needed to handle the characters that have been replaced when ISO-8859-15 was introduced (see Comparing ISO-8859-1 and ISO-8859-15). Unfortunately, it considerably increases the code size.
The below code is supposed to be easy to understand. It can be optimized for better performance if that's a main concern.
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
// a valid codepoint has been decoded; convert it to ISO-8859-15
char outc;
if (codepoint <= 255) {
// codepoints up to 255 can be directly converted wit a few exceptions
if (codepoint != 0xa4 && codepoint != 0xa6 && codepoint != 0xa8
&& codepoint != 0xb4 && codepoint != 0xb8 && codepoint != 0xbc
&& codepoint != 0xbd && codepoint != 0xbe) {
outc = static_cast<char>(codepoint);
}
else {
outc = '?';
}
}
else {
// With a few exceptions, codepoints above 255 cannot be converted
if (codepoint == 0x20AC) {
outc = 0xa4;
}
else if (codepoint == 0x0160) {
outc = 0xa6;
}
else if (codepoint == 0x0161) {
outc = 0xa8;
}
else if (codepoint == 0x017d) {
outc = 0xb4;
}
else if (codepoint == 0x017e) {
outc = 0xb8;
}
else if (codepoint == 0x0152) {
outc = 0xbc;
}
else if (codepoint == 0x0153) {
outc = 0xbd;
}
else if (codepoint == 0x0178) {
outc = 0xbe;
}
else {
outc = '?';
}
}
out.append(1, outc);
}
}
return out;
}
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
add a comment |
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1 Answer
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oldest
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oldest
votes
I like this code. It's surprisingly short. Most of the code just deals with decoding multi-byte sequences into codepoints. Once a codepoint has been decoded, the conversion to ISO-8859-1 is very simple:
- If it's less or equal 255, it's also a valid ISO-8859-1 character:
out.append(1, static_cast<char>(codepoint));
- If not, it cannot be represented in ISO-8859-1 and is replaced with a question mark:
out.append("?");
So to make it work for ISO-8859-15, more code is needed to handle the characters that have been replaced when ISO-8859-15 was introduced (see Comparing ISO-8859-1 and ISO-8859-15). Unfortunately, it considerably increases the code size.
The below code is supposed to be easy to understand. It can be optimized for better performance if that's a main concern.
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
// a valid codepoint has been decoded; convert it to ISO-8859-15
char outc;
if (codepoint <= 255) {
// codepoints up to 255 can be directly converted wit a few exceptions
if (codepoint != 0xa4 && codepoint != 0xa6 && codepoint != 0xa8
&& codepoint != 0xb4 && codepoint != 0xb8 && codepoint != 0xbc
&& codepoint != 0xbd && codepoint != 0xbe) {
outc = static_cast<char>(codepoint);
}
else {
outc = '?';
}
}
else {
// With a few exceptions, codepoints above 255 cannot be converted
if (codepoint == 0x20AC) {
outc = 0xa4;
}
else if (codepoint == 0x0160) {
outc = 0xa6;
}
else if (codepoint == 0x0161) {
outc = 0xa8;
}
else if (codepoint == 0x017d) {
outc = 0xb4;
}
else if (codepoint == 0x017e) {
outc = 0xb8;
}
else if (codepoint == 0x0152) {
outc = 0xbc;
}
else if (codepoint == 0x0153) {
outc = 0xbd;
}
else if (codepoint == 0x0178) {
outc = 0xbe;
}
else {
outc = '?';
}
}
out.append(1, outc);
}
}
return out;
}
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
add a comment |
I like this code. It's surprisingly short. Most of the code just deals with decoding multi-byte sequences into codepoints. Once a codepoint has been decoded, the conversion to ISO-8859-1 is very simple:
- If it's less or equal 255, it's also a valid ISO-8859-1 character:
out.append(1, static_cast<char>(codepoint));
- If not, it cannot be represented in ISO-8859-1 and is replaced with a question mark:
out.append("?");
So to make it work for ISO-8859-15, more code is needed to handle the characters that have been replaced when ISO-8859-15 was introduced (see Comparing ISO-8859-1 and ISO-8859-15). Unfortunately, it considerably increases the code size.
The below code is supposed to be easy to understand. It can be optimized for better performance if that's a main concern.
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
// a valid codepoint has been decoded; convert it to ISO-8859-15
char outc;
if (codepoint <= 255) {
// codepoints up to 255 can be directly converted wit a few exceptions
if (codepoint != 0xa4 && codepoint != 0xa6 && codepoint != 0xa8
&& codepoint != 0xb4 && codepoint != 0xb8 && codepoint != 0xbc
&& codepoint != 0xbd && codepoint != 0xbe) {
outc = static_cast<char>(codepoint);
}
else {
outc = '?';
}
}
else {
// With a few exceptions, codepoints above 255 cannot be converted
if (codepoint == 0x20AC) {
outc = 0xa4;
}
else if (codepoint == 0x0160) {
outc = 0xa6;
}
else if (codepoint == 0x0161) {
outc = 0xa8;
}
else if (codepoint == 0x017d) {
outc = 0xb4;
}
else if (codepoint == 0x017e) {
outc = 0xb8;
}
else if (codepoint == 0x0152) {
outc = 0xbc;
}
else if (codepoint == 0x0153) {
outc = 0xbd;
}
else if (codepoint == 0x0178) {
outc = 0xbe;
}
else {
outc = '?';
}
}
out.append(1, outc);
}
}
return out;
}
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
add a comment |
I like this code. It's surprisingly short. Most of the code just deals with decoding multi-byte sequences into codepoints. Once a codepoint has been decoded, the conversion to ISO-8859-1 is very simple:
- If it's less or equal 255, it's also a valid ISO-8859-1 character:
out.append(1, static_cast<char>(codepoint));
- If not, it cannot be represented in ISO-8859-1 and is replaced with a question mark:
out.append("?");
So to make it work for ISO-8859-15, more code is needed to handle the characters that have been replaced when ISO-8859-15 was introduced (see Comparing ISO-8859-1 and ISO-8859-15). Unfortunately, it considerably increases the code size.
The below code is supposed to be easy to understand. It can be optimized for better performance if that's a main concern.
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
// a valid codepoint has been decoded; convert it to ISO-8859-15
char outc;
if (codepoint <= 255) {
// codepoints up to 255 can be directly converted wit a few exceptions
if (codepoint != 0xa4 && codepoint != 0xa6 && codepoint != 0xa8
&& codepoint != 0xb4 && codepoint != 0xb8 && codepoint != 0xbc
&& codepoint != 0xbd && codepoint != 0xbe) {
outc = static_cast<char>(codepoint);
}
else {
outc = '?';
}
}
else {
// With a few exceptions, codepoints above 255 cannot be converted
if (codepoint == 0x20AC) {
outc = 0xa4;
}
else if (codepoint == 0x0160) {
outc = 0xa6;
}
else if (codepoint == 0x0161) {
outc = 0xa8;
}
else if (codepoint == 0x017d) {
outc = 0xb4;
}
else if (codepoint == 0x017e) {
outc = 0xb8;
}
else if (codepoint == 0x0152) {
outc = 0xbc;
}
else if (codepoint == 0x0153) {
outc = 0xbd;
}
else if (codepoint == 0x0178) {
outc = 0xbe;
}
else {
outc = '?';
}
}
out.append(1, outc);
}
}
return out;
}
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
I like this code. It's surprisingly short. Most of the code just deals with decoding multi-byte sequences into codepoints. Once a codepoint has been decoded, the conversion to ISO-8859-1 is very simple:
- If it's less or equal 255, it's also a valid ISO-8859-1 character:
out.append(1, static_cast<char>(codepoint));
- If not, it cannot be represented in ISO-8859-1 and is replaced with a question mark:
out.append("?");
So to make it work for ISO-8859-15, more code is needed to handle the characters that have been replaced when ISO-8859-15 was introduced (see Comparing ISO-8859-1 and ISO-8859-15). Unfortunately, it considerably increases the code size.
The below code is supposed to be easy to understand. It can be optimized for better performance if that's a main concern.
std::string UTF8toISO8859_1(const char * in) {
std::string out;
if (in == NULL)
return out;
unsigned int codepoint;
while (*in != 0) {
unsigned char ch = static_cast<unsigned char>(*in);
if (ch <= 0x7f)
codepoint = ch;
else if (ch <= 0xbf)
codepoint = (codepoint << 6) | (ch & 0x3f);
else if (ch <= 0xdf)
codepoint = ch & 0x1f;
else if (ch <= 0xef)
codepoint = ch & 0x0f;
else
codepoint = ch & 0x07;
++in;
if (((*in & 0xc0) != 0x80) && (codepoint <= 0x10ffff)) {
// a valid codepoint has been decoded; convert it to ISO-8859-15
char outc;
if (codepoint <= 255) {
// codepoints up to 255 can be directly converted wit a few exceptions
if (codepoint != 0xa4 && codepoint != 0xa6 && codepoint != 0xa8
&& codepoint != 0xb4 && codepoint != 0xb8 && codepoint != 0xbc
&& codepoint != 0xbd && codepoint != 0xbe) {
outc = static_cast<char>(codepoint);
}
else {
outc = '?';
}
}
else {
// With a few exceptions, codepoints above 255 cannot be converted
if (codepoint == 0x20AC) {
outc = 0xa4;
}
else if (codepoint == 0x0160) {
outc = 0xa6;
}
else if (codepoint == 0x0161) {
outc = 0xa8;
}
else if (codepoint == 0x017d) {
outc = 0xb4;
}
else if (codepoint == 0x017e) {
outc = 0xb8;
}
else if (codepoint == 0x0152) {
outc = 0xbc;
}
else if (codepoint == 0x0153) {
outc = 0xbd;
}
else if (codepoint == 0x0178) {
outc = 0xbe;
}
else {
outc = '?';
}
}
out.append(1, outc);
}
}
return out;
}
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
answered Nov 12 '18 at 21:55
CodoCodo
50.6k11110148
50.6k11110148
add a comment |
add a comment |
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1
Maybe this can help Comparing ISO-8859-1 and ISO-8859-15?
– Robert Andrzejuk
Nov 12 '18 at 20:58