diff options
Diffstat (limited to '410kern/stdio/doscan.c')
| -rw-r--r-- | 410kern/stdio/doscan.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/410kern/stdio/doscan.c b/410kern/stdio/doscan.c new file mode 100644 index 0000000..f4c0a30 --- /dev/null +++ b/410kern/stdio/doscan.c @@ -0,0 +1,181 @@ +/* + * Mach Operating System + * Copyright (c) 1993 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ +/* + * File: sscanf.c + * Author: Alessandro Forin, Carnegie Mellon University + * Date: 3/93 + * + * Parse trivially simple strings + */ + +#include <stddef.h> +#include <stdarg.h> +#include <types.h> +#include <ctype.h> +#include "doscan.h" + +/* + * All I need is a miracle ... + * to keep this from growing like all the other sscanf! + */ +int +_doscan(const char *fmt, va_list vp, + int (*getc)(void *getc_arg), + void (*ungetc)(int c, void *getc_arg), + void *getc_arg) +{ + register int c; + boolean_t neg; + boolean_t discard; + boolean_t invalid; + int vals = 0; + + while ((c = *fmt++) != 0) { + + if (c != '%') { + if (isspace(c)) + { + while (isspace(c = getc(getc_arg))); + if (c == 0) break; + ungetc(c, getc_arg); + continue; + } + else if (c == getc(getc_arg)) + continue; + else + break; /* mismatch */ + } + + discard = 0; + invalid = 1; + + more_fmt: + + c = getc(getc_arg); + if (c == 0) + break; /* end of input */ + + switch (*fmt++) { + + case 'd': + { + long n = 0; + + neg = c == '-'; + if (neg) c = getc(getc_arg); + + while (c >= '0' && c <= '9') { + n = n * 10 + (c - '0'); + c = getc(getc_arg); + invalid = 0; + } + ungetc(c, getc_arg); + + if (neg) n = -n; + + /* done, store it away */ + if (!discard) + { + int *p = va_arg(vp, int *); + *p = n; + } + + break; + } + + case 'x': + { + long n = 0; + + neg = c == '-'; + if (neg) c = getc(getc_arg); + + while (1) + { + if ((c >= '0') && (c <= '9')) + n = n * 16 + (c - '0'); + else if ((c >= 'a') && (c <= 'f')) + n = n * 16 + (c - 'a' + 10); + else if ((c >= 'A') && (c <= 'F')) + n = n * 16 + (c - 'A' + 10); + else + break; + c = getc(getc_arg); + invalid = 0; + } + ungetc(c, getc_arg); /* retract lookahead */ + + if (neg) n = -n; + + /* done, store it away */ + if (!discard) + { + int *p = va_arg(vp, int *); + *p = n; + } + + break; + } + + case 's': + { + char *buf = NULL; + + if (!discard) + buf = va_arg(vp, char *); + + while (c && !isspace(c)) + { + if (!discard) + *buf++ = c; + c = getc(getc_arg); + invalid = 0; + } + ungetc(c, getc_arg); /* retract lookahead */ + + if (!discard) + *buf = 0; + + break; + } + + case '*': + discard = 1; + goto more_fmt; + + default: + break; + } + + if (invalid) + break; + else if (!discard) + vals++; + } + + return vals; +} + |