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/* scanf.c for limited Linux libc
Copyright (C) 1996 Joel N. Weber II <nemo@koa.iolani.honolulu.hi.us>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* This scanf code was derived from my printf code, which in turn was
* derived from Alan Cox's printk. It was tested by [no one so far...]
*/
/* Disclaimer: I haven't even THOUGHT about testing this. If you do decide
* to be brave and test it, and it doesn't work, you have the following
* options:
* o Send me mail telling me it doesn't work, which I will ignore
* since I already knew that.
* o Fix it yourself
* o isolate the problem and send it to the list, and maybe
* I'll fix it
*/
/* BTW, the above comment may be destroyed once this has been tested. It's
* not nessisary for my great great grandchildren to see it when they
* take Ancient Linux History...
*/
/* Incidentally, if it doesn't work, it may well be because I never bothered
* to learn how to use scanf()...I briefly tried it for the usaco qualification
* round, but had some wierd problems...ask me after mid February...BTW the
* problems had nothing to do with scanf(); it was still broken (hopelessly)
* when I went to getchar().
*/
/* Note, too that the current version probably assumes some things with
* variable argument handling that it shouldn't. Don't expect this to
* work on a 386 in 32 bit mode, don't expect this to work on a Z80,
* or anything other than an 8086. In fact, don't expect it to even
* work on an 8086 ;-)
*/
/* One of these days the headers will work painlessly... */
/* #include <linuxmt/types.h> */
/* #include <linuxmt/fcntl.h> */
#include "stdio.h"
/* note that we assume base == 10... */
static int numin(int *num, int base, FILE *stream, int c)
{
if ((c < '0') || (c > '9')) return 0;
*num = 0;
while ((c >= '0') && (c <= '9')) {
*num = *num * base + c - '0';
c = getc(stream);
}
ungetc(c, stream);
}
/* currently, the h/l specifications are ignored */
static int internal_scanf(stream,fmt,a1)
FILE *stream;
char *fmt;
int *a1;
{
unsigned char *p=(char *)a1;
char c;
int inc;
int count = 0;
while(c=*fmt++)
{
do {
inc = getc(stream);
} while ((inc == ' ') || (inc == '\t') || (inc == '\n'));
if ((c == '\n') || (c == '\t') || (c == ' '))
;
else if (c!='%') {
if (c != inc) {
ungetc(inc, stream);
return count;
}
} else {
int len=2;
c=*fmt++;
if(c=='h') c=*fmt++;
else if(c=='l') c=*fmt++;
switch(c)
{
case 'x':
if (numin(p, 16, stream, inc)) count++;
else return count;
p+=2;
break;
case 'd':
if (numin(p, 10, stream, inc)) count++;
else return count;
p+=2;
break;
case 's':
{
char *cp=*((char **)p);
p+=sizeof(char *);
while(*cp)
putc(cp++, stream);
while ((inc != ' ') && (inc != '\t')
&& (inc != '\n') && (inc != EOF)) {
*cp++ = inc;
inc = getc(stream);
}
ungetc(inc, stream);
break;
}
case 'c':
*p++ = inc;
p++;
break;
default:
putc('?', stream);
}
}
}
return count;
}
int fscanf(stream,fmt,a1)
FILE *stream;
char *fmt;
int a1;
{
return internal_fscanf(stream,fmt,&a1);
}
int scanf(fmt,a1)
char *fmt;
int a1;
{
return internal_fscanf(stdout,fmt,&a1);
}
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