Messages in this thread Patch in this message |  | | Date | Mon, 24 Sep 2001 14:05:19 -0400 | From | Paul <> | Subject | Re: [PATCH] Fix sscanf (more fixes) |
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This patch includes my previous modifications and also corrects behaviour to match sscanf(3) as far as matching white space and avoiding a false match in some cases.
Paul set@pobox.com
--- 2.4.9-ac13-user/lib/vsprintf.c.old Fri Sep 21 19:42:25 2001 +++ 2.4.9-ac13-user/lib/vsprintf.c Mon Sep 24 13:52:05 2001 @@ -18,6 +18,7 @@ #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> +#include <linux/kernel.h> #include <asm/div64.h> @@ -515,36 +516,44 @@ int num = 0; int qualifier; int base; - unsigned int field_width; + int field_width = -1; int is_sign = 0; - for (; *fmt; fmt++) { + while(*fmt && *str) { /* skip any white space in format */ + /* white space in format matchs any amount of + * white space, including none, in the input. + */ if (isspace(*fmt)) { - continue; + while (isspace(*fmt)) + ++fmt; + while (isspace(*str)) + ++str; } /* anything that is not a conversion must match exactly */ - if (*fmt != '%') { + if (*fmt != '%' && *fmt) { if (*fmt++ != *str++) - return num; + break; continue; } + + if (!*fmt) + break; ++fmt; /* skip this conversion. * advance both strings to next white space */ if (*fmt == '*') { - while (!isspace(*fmt)) + while (!isspace(*fmt) && *fmt) fmt++; - while(!isspace(*str)) + while (!isspace(*str) && *str) str++; continue; } /* get field width */ - field_width = 0xffffffffUL; if (isdigit(*fmt)) field_width = skip_atoi(&fmt); @@ -557,25 +566,32 @@ base = 10; is_sign = 0; - switch(*fmt) { + if (!*fmt || !*str) + break; + + switch(*fmt++) { case 'c': { char *s = (char *) va_arg(args,char*); + if (field_width == -1) + field_width = 1; do { *s++ = *str++; - } while(field_width-- > 0); + } while(field_width-- > 0 && *str); num++; } continue; case 's': { char *s = (char *) va_arg(args, char *); + if(field_width == -1) + field_width = INT_MAX; /* first, skip leading white space in buffer */ while (isspace(*str)) str++; /* now copy until next white space */ - while (!isspace(*str) && field_width--) { + while (*str && !isspace(*str) && field_width--) { *s++ = *str++; } *s = '\0'; @@ -617,6 +633,9 @@ while (isspace(*str)) str++; + if (!*str || !isdigit(*str)) + break; + switch(qualifier) { case 'h': if (is_sign) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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