Re: beta12: 8-bit-cleanliness

[Thorsten Meinecke <kaefer@aglaia.snafu.de>]

Peter Stephenson wrote:
> a.main@dcs.warwick.ac.uk wrote:
> > >... nicefputs() ... niceputc() ...
> > You'll want to modify nicestrlen() as well.
> 
> Thanks.  Here's the complete patch for all three routines.

May I have a stab at thee? Think I've spotted 3 flaws in Peter's patch:

1.) The only place where nicestrlen() is called, is in stradd(), to
  determine the number of chars npputc() will put in the prompt. Which
  will break. That's why stradd() and npputc() want to be altered, too.
  
2.) The return value of isprint() depends on the system's/user's
  locale setting, leaving lots of ways to be messed with. According
  to how I understand Peter's approach, we can trust isprint() if it
  says a char is printable, but not the other way.

  So I'd rather change the order of the tests: first see if it's print-
  able, and then check if it's non-ascii, i.e. the high-order bit set,
  and then try if the char with the high-order bit stripped is printable.

  An example is the ISO-8859-1 character LATIN SMALL LETTER Y WITH
  DIAERESIS, '0xff', which would fail to print even in case a proper
  locale is provided, because '0x7f' (DEL) wouldn't necessarily print.

   (While we're at it: Is there any reason that npputc() cares about
    DEL ('0x7f') and nicefputs()/niceputc() don't? I've no trouble
    to enter that character literally into the history, and now I
    expect it to be printed nicely: '^?'  :-)

3.) char c; if isprint(c) ... doesn't work for me. The prototype in
  <ctype.h> says isprint(int). It looks again that c should be cast
  to (unsigned char), otherwise the sign is preserved when c promotes
  to int. Will STOUC() do the job here?


After my patch, zsh should be able to niceprint characters in the range
0xa0 - 0xff in addition to those from the ASCII charset. Which is OK
with ISO-8859 charsets, because characters from 0x80 to 0x9f aren't
defined (they might dump zsh's core anyway). Furthermore, I tried hard
not to break prompt truncation. Did I fail?

Forgive my boldness,
--Thorsten


*** 1.74	1995/11/16 06:31:52
--- Src/utils.c	1995/11/24 17:12:40
***************
*** 145,181 ****
  	return;
      }
      c &= 0xff;
!     if (isprint(c)) {
! 	putc(c, f);
!     } else if (c == '\n') {
! 	putc('\\', f);
! 	putc('n', f);
!     } else if (c == '\t') {
! 	putc('\\', f);
! 	putc('t', f);
!     } else {
! 	putc('^', f);
! 	putc(c ^ 0x40, f);
      }
  }
  
  /**/
  void
  nicefputs(char *s, FILE *f)
  {
!     for (; *s; s++) {
! 	if (isprint(*s))
! 	    putc(*s, f);
! 	else if (*s == '\n') {
! 	    putc('\\', f);
! 	    putc('n', f);
! 	} else if(*s == '\t') {
! 	    putc('\\', f);
! 	    putc('t', f);
! 	} else {
! 	    putc('^', f);
! 	    putc(*s ^ 0x40, f);
  	}
      }
  }
  
--- 145,185 ----
  	return;
      }
      c &= 0xff;
!     if(!isprint(c)) {
! 	if(c & 0x80 && !isprint(c & ~0x80)) {
! 	    fputs("\\M-", f);
! 	    c &= ~0x80;
! 	}
! 	switch(c) {
! 	    case '\n': putc('\\', f); c = 'n';			    break;
! 	    case '\t': putc('\\', f); c = 't';			    break;
! 	    case 0x7f: putc('^',  f); c = '?';			    break;
! 	    default:   if(!(c & 0x80)) { putc('^', f); c ^= 0x40; } break;
! 	}
      }
+     putc(c, f);
  }
  
  /**/
  void
  nicefputs(char *s, FILE *f)
  {
!     int c;
! 
!     for (; (c = STOUC(*s)); s++) {
! 	if(!isprint(c)) {
! 	    if(c & 0x80 && !isprint(c & ~0x80)) {
! 		fputs("\\M-", f);
! 		c &= ~0x80;
! 	    }
! 	    switch(c) {
! 		case '\n': putc('\\', f); c = 'n';			break;
! 		case '\t': putc('\\', f); c = 't';			break;
! 		case 0x7f: putc('^',  f); c = '?';			break;
! 		default:   if(!(c & 0x80)) { putc('^', f); c ^= 0x40; } break;
! 	    }
  	}
+ 	putc(c, f);
      }
  }
  
***************
*** 184,192 ****
  nicestrlen(char *s)
  {
      size_t l = 0;
  
!     for(; *s; s++)
! 	l += 1 + !isprint(*s);
      return l;
  }
  
--- 188,202 ----
  nicestrlen(char *s)
  {
      size_t l = 0;
+     int c;
  
!     for(; (c = STOUC(*s)); s++, l++)
! 	if(!isprint(c))
! 	    if(c & 0x80) {
! 		if(!isprint(c & ~0x80))
! 		    l += 4;
! 	    } else
! 		l++;
      return l;
  }
  
*** 1.30	1995/10/09 23:53:03
--- Src/zle_misc.c	1995/11/24 17:09:23
***************
*** 644,649 ****
--- 644,651 ----
  stradd(char *d)
  {
      int dlen = nicestrlen(d);
+     char buf[6]; buf[1] = '\0';
+ 
      addbufspc(dlen);
      if (trunclen && dlen > trunclen) {
  	char *t = truncstr + 1;
***************
*** 652,678 ****
  	addbufspc(tlen);
  	len = tlen < trunclen ? trunclen - tlen : 0;
  	if (*truncstr == '>') {
! 	    while (len-- > 0) {
! 		if(!isprint(*d))
! 		    len--;
  		npputc(*d++);
  	    }
! 	    if(len == -2)
! 		bp--;
  	    while (*t) pputc(*t++);
  	} else {
  	    while (*t) pputc(*t++);
  	    d = strchr(d, 0);
! 	    for(; len > 0; len--)
! 		if(!isprint(*--d))
! 		    len--;
! 	    if(len == -1)
! 		switch(*d) {
! 		    case '\n': *bp++ = 'n'; d++; break;
! 		    case '\t': *bp++ = 't'; d++; break;
! 		    case 0x7f: *bp++ = '?'; d++; break;
! 		    default:   *bp++ = (*d++) | 0x40;
! 		}
  	    while (*d) npputc(*d++);
  	}
  	return;
--- 654,684 ----
  	addbufspc(tlen);
  	len = tlen < trunclen ? trunclen - tlen : 0;
  	if (*truncstr == '>') {
! 	    while (len > 0) {
! 		buf[0] = *d;
! 		len -= nicestrlen(buf);
  		npputc(*d++);
  	    }
! 	    if(len < 0)
! 		bp += len;
  	    while (*t) pputc(*t++);
  	} else {
  	    while (*t) pputc(*t++);
  	    d = strchr(d, 0);
! 	    while(len > 0) {
! 		buf[0] = *--d;
! 		len -= nicestrlen(buf);
! 	    }
! 	    if(len < 0) {
! 		char *sav = bp;
! 
! 		bp = buf;
! 		npputc(*d++);
! 		*bp = '\0';
! 		for(bp = buf + -len; *bp; *sav++ = *bp++);
! 
! 		bp = sav;
! 	    }
  	    while (*d) npputc(*d++);
  	}
  	return;
***************
*** 1261,1277 ****
  
  /**/
  void
! npputc(char c)
  {
!     if(isprint(c))
! 	*bp++ = c;
!     else
  	switch(c) {
! 	    case '\n': *bp++ = '\\'; *bp++ = 'n';      break;
! 	    case '\t': *bp++ = '\\'; *bp++ = 't';      break;
! 	    case 0x7f: *bp++ = '^';  *bp++ = '?';      break;
! 	    default:   *bp++ = '^';  *bp++ = c | 0x40; break;
  	}
  }
  
  /**/
--- 1267,1288 ----
  
  /**/
  void
! npputc(char t)
  {
!     int c = STOUC(t);
! 
!     if(!isprint(c)) {
! 	if(c & 0x80 && !isprint(c & ~0x80)) {
! 	    *bp++ = '\\'; *bp++ = 'M'; *bp++ = '-'; c &= ~0x80;
! 	}	
  	switch(c) {
! 	    case '\n': *bp++ = '\\'; c = 'n';			   break;
! 	    case '\t': *bp++ = '\\'; c = 't';			   break;
! 	    case 0x7f: *bp++ = '^';  c = '?';			   break;
! 	    default:   if(!(c & 0x80)) { *bp++ = '^'; c |= 0x40; } break;
  	}
+     }
+     *bp++ = c;
  }
  
  /**/