globbing reacts to signals more quickly; new printf %Q format specifier; readline completion handles multiline quotes better

builtins/printf.def

@@ -40,6 +40,8 @@ printf interprets:
 
   %b	expand backslash escape sequences in the corresponding argument
   %q	quote the argument in a way that can be reused as shell input
+  %Q	like %q, but apply any precision to the unquoted argument before
+		quoting
   %(fmt)T	output the date-time string resulting from using FMT as a format
 	        string for strftime(3)
 
@@ -245,7 +247,7 @@ printf_builtin (list)
 {
   int ch, fieldwidth, precision;
   int have_fieldwidth, have_precision;
-  char convch, thisch, nextch, *format, *modstart, *fmt, *start;
+  char convch, thisch, nextch, *format, *modstart, *precstart, *fmt, *start;
 #if defined (HANDLE_MULTIBYTE)
   char mbch[25];		/* 25 > MB_LEN_MAX, plus can handle 4-byte UTF-8 and large Unicode characters*/
   int mbind, mblen;
@@ -338,6 +340,7 @@ printf_builtin (list)
 	{
 	  precision = fieldwidth = 0;
 	  have_fieldwidth = have_precision = 0;
+	  precstart = 0;
 
 	  if (*fmt == '\\')
 	    {
@@ -411,6 +414,8 @@ printf_builtin (list)
 		  if (*fmt == '-')
 #endif
 		    fmt++;
+		  if (DIGIT (*fmt))
+		    precstart = fmt;
 		  while (DIGIT (*fmt))
 		    fmt++;
 		}
@@ -580,12 +585,27 @@ printf_builtin (list)
 	      }
 
 	    case 'q':		/* print with shell quoting */
+	    case 'Q':
 	      {
 		char *p, *xp;
-		int r;
+		int r, mpr;
+		size_t slen;
 
 		r = 0;
 		p = getstr ();
+		/* Decode precision and apply it to the unquoted string. */
+		if (convch == 'Q' && precstart)
+		  {
+		    mpr = *precstart++ - '0';
+		    while (DIGIT (*precstart))
+		      mpr = (mpr * 10) + (*precstart++ - '0');
+		    /* Error if precision > INT_MAX here? */
+		    precision = (mpr < 0 || mpr > INT_MAX) ? INT_MAX : mpr;
+		    slen = strlen (p);
+		    /* printf precision works in bytes. */
+		    if (precision < slen)
+		      p[precision] = '\0';
+		  }
 		if (p && *p == 0)	/* XXX - getstr never returns null */
 		  xp = savestring ("''");
 		else if (ansic_shouldquote (p))
@@ -594,6 +614,12 @@ printf_builtin (list)
 		  xp = sh_backslash_quote (p, 0, 3);
 		if (xp)
 		  {
+		    if (convch == 'Q')
+		      {
+			slen = strlen (xp);
+			if (slen > precision)
+			  precision = slen;
+		      }		    
 		    /* Use printstr to get fieldwidth and precision right. */
 		    r = printstr (start, xp, strlen (xp), fieldwidth, precision);
 		    if (r < 0)
@@ -767,7 +793,7 @@ printstr (fmt, string, len, fieldwidth, precision)
       fw = (mfw < 0 || mfw > INT_MAX) ? INT_MAX : mfw;
     }
 
-  /* get precision, if present */
+  /* get precision, if present. doesn't handle negative precisions */
   if (*fmt == '.')
     {
       fmt++;
@@ -783,6 +809,8 @@ printstr (fmt, string, len, fieldwidth, precision)
 	    mpr = (mpr * 10) + (*fmt++ - '0');
 	  /* Error if precision > INT_MAX here? */
 	  pr = (mpr < 0 || mpr > INT_MAX) ? INT_MAX : mpr;
+	  if (pr < precision && precision < INT_MAX)
+	    pr = precision;		/* XXX */
 	}
       else
 	pr = 0;		/* "a null digit string is treated as zero" */