Date: Fri, 25 Jul 2025 19:35:41 +0000
From: bugzilla-noreply@freebsd.org
To: bugs@FreeBSD.org
Subject: [Bug 288440] sscanf("003", "%i", &val); returns 1 but misparses with val == 0 instead of val == 3
Message-ID: <bug-288440-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288440 Bug ID: 288440 Summary: sscanf("003", "%i", &val); returns 1 but misparses with val == 0 instead of val == 3 Product: Base System Version: CURRENT Hardware: Any URL: https://github.com/dgibson/dtc/issues/165 OS: Any Status: New Keywords: standards Severity: Affects Some People Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: mandree@FreeBSD.org FreeBSD's sscanf (and likely all siblings) are broken and can't parse "003" as 3 through %i. I suspect vfscanf.c's parseint()/parseint_fsm() which apparently don't skip the center 0 and returns with *base == 0 and *state == any, instead of setting the base to 8: if it has seen 00, it hasn't seen 0b/0B/0x/0X, so base 2 and base 16 are out of the question, and from the leading 0 prefix it's clear we're parsing octal input. Also, sscanf is in this situation (%i format string) supposed to scan as-if strtol were being used, and strtol works properly in this special case. Use case, see URL. Demo program: // this is try.c // compile and run: cc -o try try.c && ./try #include <stdlib.h> #include <stdio.h> #include <errno.h> int main() { int val; int len; int retval; retval = sscanf("003", "%i%n", &val, &len); printf("sscanf, retval = %d, val = %d, len = %d\n", retval, val, len); long longval; char *startptr = "003"; char *endptr; errno = 0; longval = strtol(startptr, &endptr, 0); printf("strtol, longval = %ld, len = %d, errno = %d\n", longval, (int)(endptr - startptr), errno); return 0; } -- You are receiving this mail because: You are the assignee for the bug.home | help
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