text: #include <stdint.h>
  #include <stdio.h>
  
  #include "u8decode.h"
  
  void
  safe_u8putstr(char *s0, size_t l, int oneline, FILE *stream)
  {
  	// tty-safe output of s, with relaxed utf-8 semantics:
  	// - C0 and C1 are displayed as escape sequences
  	// - valid utf-8 is printed as is
  	// - rest is assumed to be latin-1, and translated into utf-8
  	// - translate CRLF to CR
  
  	unsigned char *s = (unsigned char *)s0;
  	unsigned char *e = s + l;
  	uint32_t c;
  
  	while (s < e) {
  		int l = u8decode((char *)s, &c);
  		if (l == -1) {
  			l = 1;
  			if (*s <= 0x9fu) {
  				// C1
  				fputc(0xe2, stream);
  				fputc(0x90, stream);
  				fputc(0x80+0x1b, stream);
  
  				fputc(0xe2, stream);
  				fputc(0x90, stream);
  				fputc(*s, stream);
  			} else {
  				/* invalid utf-8, assume it was latin-1 */
  				fputc(0xc0 | (*s >> 6), stream);
  				fputc(0x80 | (*s & 0x3f), stream);
  			}
  		} else if (c < 32 &&
  		    *s != ' ' && *s != '\t' &&
  		    (oneline || (*s != '\n' && *s != '\r'))) {
  			// NUL
  			if (l == 0)
  				l = 1;
  			// C0
  			fputc(0xe2, stream);
  			fputc(0x90, stream);
  			fputc(0x80+*s, stream);
  		} else if (c == 127) {
  			// DEL
  			fputc(0xe2, stream);
  			fputc(0x90, stream);
  			fputc(0xa1, stream);
  		} else if (c == '\r') {
  			if (e - s > 1 && s[1] == '\n')
  				s++;
  			fputc(*s, stream);
  		} else {
  			fwrite(s, 1, l, stream);
  		}
  		s += l;
  	}
  }
  