PATCH: simple checks (_perf)

[hannibal20]

I've been working with smtp_perf checks. This check always returns 0.0 in beta 1.3.2, but was ok in 1.1.5. This patch fixes what was lost in some code refactoring I suppose:

$ diff src/libs/zbxsysinfo/common/common.c src/libs/zbxsysinfo/common/common.c.orig 
1620c1620
<       if( strncmp(buf, expect, strlen(expect)) == 0 )
---
>       if( strcmp(buf, expect) == 0 )

[Alexei]

Thanks for reporting this. Your patch has been integrated.

[medic]

very strange diff ...
as "expect" is hardcoded, i dont see any problem here, although the use of strncmp() is more appreciated. These functions should be equal to each other in returnvalues ..

could it already have been fixed by the patch you applied by the request of me (smtp service check broken), when the service appeared offline, because of the logic-bug ?

[Alexei]

These functions should be equal to each other in returnvalues ..

Think of strcmp("expect123","expect")!=strncmp("expect123", "expect",sizeof("expect"))

[medic]

Think of strcmp("expect123","expect")!=strncmp("expect123", "expect",sizeof("expect"))

You really sure ?
case 1 will try to find s2 in s1, but at least until one of the strings ends ...
is s2 found in s1, and s2 ends, it returns 1.
is s2 equal to s1 it returns 0
is s2 not found in s1, it returns -1

case 2 will try to find s2 in s1, but at least until one of the strings ends, or "sizeof("expect")" (n=chars+1 [cause of the nullbyte]) bytes are compared.
is s2 found in s1, after s2 ends or n bytes are read, it returns 1.
is s2 equal to s1 after s2 ends or n bytes it returns 0
is s2 not found in s1 after s2 ends or n bytes are read, it returns -1

at least this is way strcmp() strncmp() works on linux, and i'd guess *BSD it's the same ...
I wrote a small program to find out if there's a bug in strcmp, but there isnt. the main reason for existing strncmp is to prevent BOFs, there is no (and should be no) diffrence in functionality ..


#include <string.h>
#include <stdio.h>

int main () {

printf("%d\n",strcmp("expect123","expect"));
printf("%d\n",strncmp("expect123","expect",sizeof( "expect")));
printf("%d\n",strncmp("expect123","expect",sizeof( "expect")-1)); // strip off nullbyte

return(0);
}


medic@growsome ~ $ ./test2
1 # found but not equal
1 # found but not equal, because \0 != "1"
0 # equal