Just trying to output this unicode character ☒ in C using MinGW. I first put it on a buffer using swprintf, and then write it to the stdout using wprintf.
#include <stdio.h>
int main(int argc, char **argv)
{
wchar_t buffer[50];
wchar_t c = L'☒';
swprintf(buffer, L"The character is: %c.", c);
wprintf(buffer);
return 0;
}
The output under Windows 8 is:
The character is: .
Other characters such as Ɣ doesn't work neither.
What I am doing wrong?
You're using %c, but %c is for char, even when you use it from wprintf(). Use %lc, because the parameter is whar_t.
swprintf(buffer, L"The character is: %lc.", c);
This kind of error should normally be caught by compiler warnings, but it doesn't always happen. In particular, catching this error is tricky because both %c and %lc actually take int arguments, not char and wchar_t (the difference is how they interpret the int).
To output Unicode (or to be more precise UTF-16LE) to the Windows console, you have to change the file translation mode to _O_U16TEXT or _O_WTEXT. The latter one includes the BOM which isn't of interest in this case.
The file translation mode can be changed with _setmode. But it takes a file descriptor (abbreviated fd) and not a FILE *! You can get the corresponding fd from a FILE * with _fileno.
Here's an example that should work with MinGW and its variants, and also with various Visual Studio versions.
#define _CRT_NON_CONFORMING_SWPRINTFS
#include <stdio.h>
#include <io.h>
#include <fcntl.h>
int
main(void)
{
wchar_t buffer[50];
wchar_t c = L'Ɣ';
_setmode(_fileno(stdout), _O_U16TEXT);
swprintf(buffer, L"The character is: %c.", c);
wprintf(buffer);
return 0;
}
This works for me:
#include <locale.h>
#include <stdio.h>
#include <wchar.h>
int main(int argc, char **argv)
{
wchar_t buffer[50];
wchar_t c = L'☒';
if (!setlocale(LC_CTYPE, "")) {
fprintf(stderr, "Cannot set locale\n");
return 1;
}
swprintf(buffer, sizeof buffer, L"The character is %lc.", c);
wprintf(buffer);
return 0;
}
What I changed:
I added wchar.h include required by the use of swprintf
I added size as the second argument of swprintf as required by C
I changed %c conversion specification to %lc
I change locale using setlocale
This FAQ explains how to use UniCode / wide characters in MinGW:
https://sourceforge.net/p/mingw-w64/wiki2/Unicode%20apps/
Related
I would like to understand why I can print the character 'à' with the functions fopen and fgetc when I read a .txt file but I can't assign it to a char variable and print it with the printf function.
When I read the file texte.txt, the output is:
(Here is a letter that we often use in French: à)
The letter 'à' is correctly read by the fgetc function and assigned to the char c variable
See the code below:
int main() {
FILE *fp;
fp=fopen("texte.txt", "r");
if (fp==NULL) {
printf("erreur fopen");
return 1;
}
char c = fgetc(fp);
while(c != EOF) {
printf("%c", c);
c = fgetc(fp);
}
printf("\n");
return 0;
}
But now if I try to assign the 'à' character to a char variable, I get an error!
See the code below:
int main() {
char myChar = 'à';
printf("myChar is: %c\n", myChar);
return 0;
}
ERROR:
./main.c:26:15: error: character too large for enclosing character literal type
char myChar = 'à';
My knowledge in C is very insufficient, and I can't find an answer anywhere
To print à you can use wide character (or wide string):
#include <wchar.h> // wchar_t
#include <stdio.h>
#include <locale.h> // setlocale LC_ALL
int main() {
setlocale(LC_ALL, "");
wchar_t a = L'à';
printf("%lc\n", a);
}
In short: Characters have encoding. Program "locale" chooses what encoding is used by the standard library functions. A wide character represents a locale-agnostic character, a character that is "able" to be converted to/from any locale. setlocale set's your program locale to the locale of your terminal. This is needed so that printf knows how to convert wide character à to the encoding of your terminal. L in front of a character or string makes it a wide. On Linux, wide characters are in UTF-32.
Handling encodings might be hard. I can point to: https://en.wikipedia.org/wiki/Character_encoding , https://en.wikipedia.org/wiki/ASCII , https://www.gnu.org/software/libc/manual/html_node/Extended-Char-Intro.html , https://en.cppreference.com/w/cpp/locale , https://en.wikipedia.org/wiki/Unicode .
You can encode a multibyte string straight in your source code and output. This will work only if your compiler generates code for the multibyte string in the same encoding as your terminal works with. If you change your terminal encoding, or tell your compiler to use a different encoding, it may fail. On Linux, UTF-8 is everywhere, compilers generate UTF-8 string and terminals understand UTF-8.
const char *str = "à";
printf("%s\n", str);
I am trying to print "□" and "■" using c.
I tried printf("%c", (char)254u); but it didn't work.
Any help? Thank you!
I do not know what is (char)254u in your code. First you set locale to unicode, next you just printf it. That is it.
#include <locale.h>
#include <stdio.h>
int main()
{
setlocale(LC_CTYPE, "en_US.UTF-8");
printf("%lc", u'□');
return 0;
}
You can use directly like this :
#include <stdio.h>
int main()
{
printf("■");
return 0;
}
You can print Unicode characters using _setmode.
Sets the file translation mode. learn more
#include <fcntl.h>
#include <stdio.h>
#include <io.h>
int main(void) {
_setmode(_fileno(stdout), _O_U16TEXT);
wprintf(L"\x25A0\x25A1\n");
return 0;
}
output
■□
As other answers have mentioned, you have need to set the proper locale to use the UTF-8 encoding, defined by the Unicode Standard. Then you can print it with %lc using any corresponding number. Here is a minimal code example:
#include <stdio.h>
#include <locale.h>
int main() {
setlocale(LC_CTYPE, "en_US.UTF-8"); // Defined proper UTF-8 locale
printf("%lc\n", 254); // Using '%lc' to specify wchar_t instead of char
return 0;
}
If you want to store it in a variable, you must use a wchar_t, which allows the number to be mapped to its Unicode symbol. This answer provides more detail.
wchar_t x = 254;
printf("%lc\n", x);
I've written a small C program:
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
int main() {
wprintf(L"%s\n", setlocale(LC_ALL, "C.UTF-8"));
wchar_t chr = L'┐';
wprintf(L"%c\n", chr);
}
Why doesn't this print the character ┐ ?
Instead it prints gibberish.
I've checked:
tried compiling without setlocale, same result
the terminal itself can print the character, I can copy-paste it to terminal from text-editor, it's gnome-terminal on Ubuntu
GCC version is 4.8.2
wprintf is a version of printf which takes a wide string as its format string, but otherwise behaves just the same: %c is still treated as char, not wchar_t. So instead you need to use %lc to format a wide character. And since your strings are ASCII you may as well use printf. For example:
int main() {
printf("%s\n", setlocale(LC_ALL, "C.UTF-8"));
wchar_t chr = L'┐';
printf("%lc\n", chr);
}
I am trying to read Chinese characters from an infile, and I have found a few questions on the subject here but nothing that works for me or suits my needs. I am using the fread() implementation from this question, but it is not working. I am running Linux.
#define UNICODE
#ifdef UNICODE
#define _UNICODE
#else
#define _MBCS
#endif
#include <locale.h>
#include <stdio.h>
#include <wchar.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char * argv[]) {
FILE *infile = fopen(argv[1], "r");
wchar_t test[2] = L"\u4E2A";
setlocale(LC_ALL, "");
printf("%ls\n", test); //test
wcscpy(test, L"\u4F60"); //test
printf("%ls\n", test); //test
for (int i = 0; i < 5; i++){
fread(test, 2, 2, infile);
printf("%ls\n", test);
}
return 0;
}
I use the following text file to test it:
一个人
两本书
三张桌子
我喜欢一个猫
and the program outputs:
个
你
������
Anyone have any wisdom on the subject?
Edit: Also, that's all of my code because I'm not sure where it fails. There's some stuff in there where I test to make sure I can print unicode wchars that isn't entirely relevant to the question.
If you really need to read a UTF-8 (or rather a locale charmap) file one codepoint at a time you can use fscanf as below. But do note, this is codepoints not characters, characters may consist of multiple codepoints because of combining codes and some of the codepoints are most definitely not printable.
#include <locale.h>
#include <stdio.h>
#include <wchar.h>
#include <string.h>
#include <stdlib.h>
int
main(int argc, char *argv[])
{
FILE *infile = fopen(argv[1], "r");
wchar_t test[2] = L"\u4E2A";
setlocale(LC_ALL, "");
printf("%ls\n", test); //test
wcscpy(test, L"\u4F60"); //test
printf("%ls\n", test); //test
for (int i = 0; i < 5; i++) {
fscanf(infile, "%1ls", test);
printf("%ls\n", test);
}
return 0;
}
Most of the time you probably won't need to use the locale functionality because UTF-8 generally just works if you treat it as an opaque encoding. Part of this is because all non ASCII characters have all their component bytes in the 128..253 range (not a typo, 254 and 255 are unused) another part is that the bytes 128..159 are always continuation bytes all the start bytes for characters are 160..253 which means an error will just break one character not the rest of the stream. (Okay, codepoints vs characters is only really there to try to convince you that dividing UTF-8 up into "characters" probably won't do what you want).
You are telling fread to read two 2-byte values in each call; however, the characters you want to read have 3-byte UTF-8 encodings. In general, you need to decode the UTF-8 stream as a whole, not in fixed-sized byte chunks.
I want to store a string with characters from extend ascii table, and print them.
I tried:
wchar_t wp[] = L"Росси́йская Акаде́мия Нау́к ";
printf("%S", wp);
I can compile but when I run it, nothing is actually displayed in my terminal.
Could you help me please?
Edit: In response to this comment:
wprintf(L"%s", wp);
Sorry, I forgot to mention that I can only use write(), as was only using printf for my first attempts.
If you want wide chars (16 bit each) as output, use the following code, as suggested by Michael:
wprintf(L"%s", wp);
If you need utf8 output, you have to use iconv() for conversion between the two. See question 7469296 as a starting point.
You need to call setlocale() first and use %ls in printf():
#include <stdio.h>
#include <wchar.h>
#include <locale.h>
int main(int argc, char *argv[])
{
setlocale(LC_ALL, "");
// setlocale(LC_ALL, "C.UTF-8"); // this also works
wchar_t wp[] = L"Росси́йская Акаде́мия Нау́к";
printf("%ls\n", wp);
return 0;
}
For more about setlocale(), refer to Displaying wide chars with printf