diff options
Diffstat (limited to 'libc/stdio1/scanf.c')
| -rw-r--r-- | libc/stdio1/scanf.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/libc/stdio1/scanf.c b/libc/stdio1/scanf.c new file mode 100644 index 0000000..81900a1 --- /dev/null +++ b/libc/stdio1/scanf.c @@ -0,0 +1,151 @@ +/* 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); +} |