{"id":2721,"date":"2018-02-22T18:20:55","date_gmt":"2018-02-23T00:20:55","guid":{"rendered":"http:\/\/www.logikalsolutions.com\/wordpress\/?p=2721"},"modified":"2018-02-22T18:21:26","modified_gmt":"2018-02-23T00:21:26","slug":"its-okay-to-hate-the-12-year-old-boys-who-write-the-bulk-of-opensource-code","status":"publish","type":"post","link":"https:\/\/www.logikalsolutions.com\/wordpress\/information-technology\/its-okay-to-hate-the-12-year-old-boys-who-write-the-bulk-of-opensource-code\/","title":{"rendered":"It’s okay to hate the 12 year old boys who write the bulk of OpenSource code"},"content":{"rendered":"

Even if their biological clock states they are north of 40, they never got past 12 when it comes to coding. In case you can’t see the featured image, the source file came from here<\/a>. And since they will _hopefully_ sweep that up, here is the first snippet.<\/p>\n

\/* this creates a timestamp based on current time according to the\r\n * fine rules of RFC3164, most importantly it ensures in a portable\r\n * way that the month day is correctly written (with a SP instead\r\n * of a leading 0). The function uses a static buffer which is\r\n * overwritten on the next call (just like ctime() does).\r\n *\/\r\nstatic char const *rfc3164_current_time(void)\r\n{\r\n\tstatic char time[32];\r\n\tstruct timeval tv;\r\n\tstruct tm *tm;\r\n\tstatic char const * const monthnames[] = {\r\n\t\t\"Jan\", \"Feb\", \"Mar\", \"Apr\", \"May\", \"Jun\", \"Jul\", \"Aug\",\r\n\t\t\"Sep\", \"Oct\", \"Nov\", \"Dec\"\r\n\t};\r\n\r\n\tlogger_gettimeofday(&tv, NULL);\r\n\ttm = localtime(&tv.tv_sec);\r\n\tsnprintf(time, sizeof(time),\"%s %2d %2.2d:%2.2d:%2.2d\",\r\n\t\tmonthnames[tm->tm_mon], tm->tm_mday,\r\n\t\ttm->tm_hour, tm->tm_min, tm->tm_sec);\r\n\treturn time;\r\n}<\/pre>\n
The second problem is they are returning the address of a variable which is inside of the function. Those bounding {} of the function delineate the scope. The static qualifier means the function is only visible from within this source file. So, to try and defeat this, our little 12 year old stuck a static qualifier on the character array (string). ___Maybe___ in the latest and greatest C standard (which I haven’t read) the compiler is now required to BOTH save the value AND keep it externally accessible while the rest of the routine is being garbage collected away.<\/p>\n
You see, the definition which was\/is in most of the compilers out there, especially those which stopped updating at C99 or a bit sooner, that’s not a requirement. The “requirement” was that the variable only be initialized once and that it retain its value across multiple function calls. There was\/is nothing about it still being externally accessible.<\/p>\n
When you are writing OpenSource, you aren’t writing for the latest and greatest, you are writing for whatever happens to be out there.<\/p>\n
While we are at it, choose “time” for a variable name, especially for a string, is Uber stupid. I couldn’t believe it compiled. My gut tells me that if this code really is working on PC platforms it is working due to a bad architecture and compiler with shit garbage collection.<\/p>\n
Don’t worry, I’m not going to cover it all, this would be\u00a0 a 2+ million word blog post if I did that.<\/p>\n
#define NILVALUE \"-\"\r\nstatic void syslog_rfc3164_header(struct logger_ctl *const ctl)\r\n{\r\n\tchar pid[30], *hostname;\r\n\r\n\t*pid = '\\0';\r\n\tif (ctl->pid)\r\n\t\tsnprintf(pid, sizeof(pid), \"[%d]\", ctl->pid);\r\n\r\n\tif ((hostname = logger_xgethostname())) {\r\n\t\tchar *dot = strchr(hostname, '.');\r\n\t\tif (dot)\r\n\t\t\t*dot = '\\0';\r\n\t} else\r\n\t\thostname = xstrdup(NILVALUE);\r\n\r\n\txasprintf(&ctl->hdr, \"<%d>%.15s %s %.200s%s: \",\r\n\t\t ctl->pri, rfc3164_current_time(), hostname, ctl->tag, pid);\r\n\r\n\tfree(hostname);\r\n}\r\n\r\n<\/pre>\n
You see, I started cross compiling this because adding all of the advertised features to the existing logger for OpenVMS was going to take several days to a week. Cross compiling this _should_ have been quicker. Yes, the current C compiler<\/p>\n
$ cc\/ver
\nHP C V7.1-015 on OpenVMS Alpha V8.3<\/p>\n
Stopped around the time of the C99 standard. I won’t go so far as to say C99 is “all” there. I’ve banged into some partially implemented stuff with the networks, but haven’t dug in to see if they are part of the standard or not.<\/p>\n
So the above snippet nests a call to our original snippet inside of a print routine. Once this got ported to OpenVMS I could step through the first snippet and see a perfectly formatted date string. When the sprintf() got done I had a big block-o-nothin where the date should be.<\/p>\n
Old Timers, we know these things. Global data isn’t a bad thing, it exists because we need it. All of these little tricks trying to bob and weave around the Grim Reaper of garbage collection are just time bombs waiting to go off. So, a quick cut and paste moving that static char definition of time to global scope brought about the expected compilation error.<\/p>\n
static char time[32]; \/* place to store a time return value *\/\r\n............^\r\n%CC-W-MIXLINKAGE, In this declaration, \"time\" is declared with both internal and external linkage. The previous declaration is at l\r\nine number 378 in file SYS$COMMON:[SYSLIB]DECC$RTLDEF.TLB;1 (text module TIME).\r\nat line number 112 in file RADIAN_ROOT:[2018-VMS-SYSLOG]logger.c;148<\/pre>\n
So, changing time[32] to time_str[32] and changing the few references to it brought about the desired outcome. What “could” have been the problem?<\/p>\n