Retro68/gcc/newlib/libc/stdio/sccl.c

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/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* Split from vfscanf.c */
#include <_ansi.h>
#include <reent.h>
#include <newlib.h>
#include <stdio.h>
#include "local.h"
/*
* Fill in the given table from the scanset at the given format
* (just after `['). Return a pointer to the character past the
* closing `]'. The table has a 1 wherever characters should be
* considered part of the scanset.
*/
u_char *
_DEFUN(__sccl, (tab, fmt),
register char *tab _AND
register u_char *fmt)
{
register int c, n, v;
/* first `clear' the whole table */
c = *fmt++; /* first char hat => negated scanset */
if (c == '^')
{
v = 1; /* default => accept */
c = *fmt++; /* get new first char */
}
else
v = 0; /* default => reject */
/* should probably use memset here */
for (n = 0; n < 256; n++)
tab[n] = v;
if (c == 0)
return fmt - 1; /* format ended before closing ] */
/*
* Now set the entries corresponding to the actual scanset to the
* opposite of the above.
*
* The first character may be ']' (or '-') without being special; the
* last character may be '-'.
*/
v = 1 - v;
for (;;)
{
tab[c] = v; /* take character c */
doswitch:
n = *fmt++; /* and examine the next */
switch (n)
{
case 0: /* format ended too soon */
return fmt - 1;
case '-':
/*
* A scanset of the form [01+-] is defined as `the digit 0, the
* digit 1, the character +, the character -', but the effect of a
* scanset such as [a-zA-Z0-9] is implementation defined. The V7
* Unix scanf treats `a-z' as `the letters a through z', but treats
* `a-a' as `the letter a, the character -, and the letter a'.
*
* For compatibility, the `-' is not considerd to define a range if
* the character following it is either a close bracket (required by
* ANSI) or is not numerically greater than the character we just
* stored in the table (c).
*/
n = *fmt;
if (n == ']' || n < c)
{
c = '-';
break; /* resume the for(;;) */
}
fmt++;
do
{ /* fill in the range */
tab[++c] = v;
}
while (c < n);
#if 1 /* XXX another disgusting compatibility hack */
/*
* Alas, the V7 Unix scanf also treats formats such
* as [a-c-e] as `the letters a through e'. This too
* is permitted by the standard....
*/
goto doswitch;
#else
c = *fmt++;
if (c == 0)
return fmt - 1;
if (c == ']')
return fmt;
#endif
break;
case ']': /* end of scanset */
return fmt;
default: /* just another character */
c = n;
break;
}
}
/* NOTREACHED */
}