Mirror of :pserver:cvs@cvs.fefe.de:/cvs libowfat https://www.fefe.de/libowfat/
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#include "fmt.h"
#ifdef UNITTEST
#undef UNITTEST
#include "fmt_tohex.c"
#define UNITTEST
#endif
static void fmt_hex4(char* dest,uint16_t w) {
dest[3]=fmt_tohex(w&0xf); w>>=4;
dest[2]=fmt_tohex(w&0xf); w>>=4;
dest[1]=fmt_tohex(w&0xf); w>>=4;
dest[0]=fmt_tohex(w&0xf);
}
size_t fmt_escapecharjson(char* dest,uint32_t ch) {
size_t n;
switch (ch) {
case '\b':
ch='b'; goto simple;
case '\n':
ch='n'; goto simple;
case '\r':
ch='r'; goto simple;
case '"':
case '\\':
case '/':
simple:
if (dest) {
dest[0]='\\';
dest[1]=(char)ch;
}
return 2;
}
if (ch>0xffff) {
if (ch>0x10ffff) return 0; // highest representable unicode codepoint
if (dest) {
dest[0]='\\';
dest[1]='u';
fmt_hex4(dest+2,(uint16_t)(0xd800 | (((ch-0x10000)>>10)&0x3ff)));
dest+=6;
}
ch=(ch&0x3ff)|0xdc00;
n=6;
} else
n=0;
if (dest) {
dest[0]='\\';
dest[1]='u';
fmt_hex4(dest+2,(uint16_t)ch);
}
return n+6;
}
#ifdef UNITTEST
#include <assert.h>
#include <string.h>
int main() {
char buf[100];
assert(fmt_escapecharjson(buf,'f')==6 && !memcmp(buf,"\\u0066",6));
assert(fmt_escapecharjson(buf,'\b')==2 && !memcmp(buf,"\\b",2));
assert(fmt_escapecharjson(buf,'\n')==2 && !memcmp(buf,"\\n",2));
assert(fmt_escapecharjson(buf,'\r')==2 && !memcmp(buf,"\\r",2));
assert(fmt_escapecharjson(buf,'"')==2 && !memcmp(buf,"\\\"",2));
assert(fmt_escapecharjson(buf,'\\')==2 && !memcmp(buf,"\\\\",2));
assert(fmt_escapecharjson(buf,'/')==2 && !memcmp(buf,"\\/",2)); /* I'm baffled as well */
assert(fmt_escapecharjson(buf,0x1d11e)==12 && !memcmp(buf,"\\ud834\\udd1e",12)); /* utf-16 surrogate pairs */
return 0;
}
#endif