utility.cpp

   1 /*
   2  * utility.cpp
   3  *
   4  * Home page of code is: http://www.smartmontools.org
   5  *
   6  * Copyright (C) 2002-12 Bruce Allen
   7  * Copyright (C) 2008-16 Christian Franke
   8  * Copyright (C) 2000 Michael Cornwell <cornwell@acm.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2, or (at your option)
  13  * any later version.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * (for example COPYING); If not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * This code was originally developed as a Senior Thesis by Michael Cornwell
  19  * at the Concurrent Systems Laboratory (now part of the Storage Systems
  20  * Research Center), Jack Baskin School of Engineering, University of
  21  * California, Santa Cruz. http://ssrc.soe.ucsc.edu/
  22  *
  23  */
  24
  25 // THIS FILE IS INTENDED FOR UTILITY ROUTINES THAT ARE APPLICABLE TO
  26 // BOTH SCSI AND ATA DEVICES, AND THAT MAY BE USED IN SMARTD,
  27 // SMARTCTL, OR BOTH.
  28
  29 #include "config.h"
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <time.h>
  34 #include <errno.h>
  35 #include <stdlib.h>
  36 #include <ctype.h>
  37 #include <stdarg.h>
  38 #include <sys/stat.h>
  39 #ifdef HAVE_LOCALE_H
  40 #include <locale.h>
  41 #endif
  42 #ifdef _WIN32
  43 #include <mbstring.h> // _mbsinc()
  44 #endif
  45
  46 #include <stdexcept>
  47
  48 #include "svnversion.h"
  49 #include "int64.h"
  50 #include "utility.h"
  51
  52 #include "atacmds.h"
  53 #include "dev_interface.h"
  54
  55 const char * utility_cpp_cvsid = "$Id: utility.cpp 4309 2016-04-24 14:59:15Z chrfranke $"
  56                                  UTILITY_H_CVSID INT64_H_CVSID;
  57
  58 const char * packet_types[] = {
  59         "Direct-access (disk)",
  60         "Sequential-access (tape)",
  61         "Printer",
  62         "Processor",
  63         "Write-once (optical disk)",
  64         "CD/DVD",
  65         "Scanner",
  66         "Optical memory (optical disk)",
  67         "Medium changer",
  68         "Communications",
  69         "Graphic arts pre-press (10)",
  70         "Graphic arts pre-press (11)",
  71         "Array controller",
  72         "Enclosure services",
  73         "Reduced block command (simplified disk)",
  74         "Optical card reader/writer"
  75 };
  76
  77 // BUILD_INFO can be provided by package maintainers
  78 #ifndef BUILD_INFO
  79 #define BUILD_INFO "(local build)"
  80 #endif
  81
  82 // Make version information string
  83 std::string format_version_info(const char * prog_name, bool full /*= false*/)
  84 {
  85   std::string info = strprintf(
  86     "%s " PACKAGE_VERSION " "
  87 #ifdef SMARTMONTOOLS_SVN_REV
  88       SMARTMONTOOLS_SVN_DATE " r" SMARTMONTOOLS_SVN_REV
  89 #else
  90       "(build date " __DATE__ ")" // checkout without expansion of Id keywords
  91 #endif
  92       " [%s] " BUILD_INFO "\n"
  93     "Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org\n",
  94     prog_name, smi()->get_os_version_str().c_str()
  95   );
  96   if (!full)
  97     return info;
  98
  99   info += "\n";
 100   info += prog_name;
 101   info += " comes with ABSOLUTELY NO WARRANTY. This is free\n"
 102     "software, and you are welcome to redistribute it under\n"
 103     "the terms of the GNU General Public License; either\n"
 104     "version 2, or (at your option) any later version.\n"
 105     "See http://www.gnu.org for further details.\n"
 106     "\n"
 107     "smartmontools release " PACKAGE_VERSION
 108       " dated " SMARTMONTOOLS_RELEASE_DATE " at " SMARTMONTOOLS_RELEASE_TIME "\n"
 109 #ifdef SMARTMONTOOLS_SVN_REV
 110     "smartmontools SVN rev " SMARTMONTOOLS_SVN_REV
 111       " dated " SMARTMONTOOLS_SVN_DATE " at " SMARTMONTOOLS_SVN_TIME "\n"
 112 #else
 113     "smartmontools SVN rev is unknown\n"
 114 #endif
 115     "smartmontools build host: " SMARTMONTOOLS_BUILD_HOST "\n"
 116     "smartmontools build with: "
 117 #if   __cplusplus > 201402
 118                                "C++17"
 119 #elif __cplusplus > 201103
 120                                "C++14"
 121 #elif __cplusplus > 199711
 122                                "C++11"
 123 #else
 124                                "C++98"
 125 #endif
 126 #if defined(__GNUC__) && defined(__VERSION__) // works also with CLang
 127                                      ", GCC " __VERSION__
 128 #endif
 129                                                           "\n"
 130     "smartmontools configure arguments:"
 131   ;
 132   info += (sizeof(SMARTMONTOOLS_CONFIGURE_ARGS) > 1 ?
 133            SMARTMONTOOLS_CONFIGURE_ARGS : " [no arguments given]");
 134   info += '\n';
 135
 136   return info;
 137 }
 138
 139 // Solaris only: Get site-default timezone. This is called from
 140 // UpdateTimezone() when TZ environment variable is unset at startup.
 141 #if defined (__SVR4) && defined (__sun)
 142 static const char *TIMEZONE_FILE = "/etc/TIMEZONE";
 143
 144 static char *ReadSiteDefaultTimezone(){
 145   FILE *fp;
 146   char buf[512], *tz;
 147   int n;
 148
 149   tz = NULL;
 150   fp = fopen(TIMEZONE_FILE, "r");
 151   if(fp == NULL) return NULL;
 152   while(fgets(buf, sizeof(buf), fp)) {
 153     if (strncmp(buf, "TZ=", 3))    // searches last "TZ=" line
 154       continue;
 155     n = strlen(buf) - 1;
 156     if (buf[n] == '\n') buf[n] = 0;
 157     if (tz) free(tz);
 158     tz = strdup(buf);
 159   }
 160   fclose(fp);
 161   return tz;
 162 }
 163 #endif
 164
 165 // Make sure that this executable is aware if the user has changed the
 166 // time-zone since the last time we polled devices. The cannonical
 167 // example is a user who starts smartd on a laptop, then flies across
 168 // time-zones with a laptop, and then changes the timezone, WITHOUT
 169 // restarting smartd. This is a work-around for a bug in
 170 // GLIBC. Yuk. See bug number 48184 at http://bugs.debian.org and
 171 // thanks to Ian Redfern for posting a workaround.
 172
 173 // Please refer to the smartd manual page, in the section labeled LOG
 174 // TIMESTAMP TIMEZONE.
 175 void FixGlibcTimeZoneBug(){
 176 #if __GLIBC__
 177   if (!getenv("TZ")) {
 178     putenv((char *)"TZ=GMT"); // POSIX prototype is 'int putenv(char *)'
 179     tzset();
 180     putenv((char *)"TZ");
 181     tzset();
 182   }
 183 #elif _WIN32
 184   if (!getenv("TZ")) {
 185     putenv("TZ=GMT");
 186     tzset();
 187     putenv("TZ=");  // empty value removes TZ, putenv("TZ") does nothing
 188     tzset();
 189   }
 190 #elif defined (__SVR4) && defined (__sun)
 191   // In Solaris, putenv("TZ=") sets null string and invalid timezone.
 192   // putenv("TZ") does nothing.  With invalid TZ, tzset() do as if
 193   // TZ=GMT.  With TZ unset, /etc/TIMEZONE will be read only _once_ at
 194   // first tzset() call.  Conclusion: Unlike glibc, dynamic
 195   // configuration of timezone can be done only by changing actual
 196   // value of TZ environment value.
 197   enum tzstate { NOT_CALLED_YET, USER_TIMEZONE, TRACK_TIMEZONE };
 198   static enum tzstate state = NOT_CALLED_YET;
 199
 200   static struct stat prev_stat;
 201   static char *prev_tz;
 202   struct stat curr_stat;
 203   char *curr_tz;
 204
 205   if(state == NOT_CALLED_YET) {
 206     if(getenv("TZ")) {
 207       state = USER_TIMEZONE; // use supplied timezone
 208     } else {
 209       state = TRACK_TIMEZONE;
 210       if(stat(TIMEZONE_FILE, &prev_stat)) {
 211         state = USER_TIMEZONE;  // no TZ, no timezone file; use GMT forever
 212       } else {
 213         prev_tz = ReadSiteDefaultTimezone(); // track timezone file change
 214         if(prev_tz) putenv(prev_tz);
 215       }
 216     }
 217     tzset();
 218   } else if(state == TRACK_TIMEZONE) {
 219     if(stat(TIMEZONE_FILE, &curr_stat) == 0
 220        && (curr_stat.st_ctime != prev_stat.st_ctime
 221             || curr_stat.st_mtime != prev_stat.st_mtime)) {
 222       // timezone file changed
 223       curr_tz = ReadSiteDefaultTimezone();
 224       if(curr_tz) {
 225         putenv(curr_tz);
 226         if(prev_tz) free(prev_tz);
 227         prev_tz = curr_tz; prev_stat = curr_stat;
 228       }
 229     }
 230     tzset();
 231   }
 232 #endif
 233   // OTHER OS/LIBRARY FIXES SHOULD GO HERE, IF DESIRED.  PLEASE TRY TO
 234   // KEEP THEM INDEPENDENT.
 235   return;
 236 }
 237
 238 #ifdef _WIN32
 239 // Fix strings in tzname[] to avoid long names with non-ascii characters.
 240 // If TZ is not set, tzset() in the MSVC runtime sets tzname[] to the
 241 // national language timezone names returned by GetTimezoneInformation().
 242 static char * fixtzname(char * dest, int destsize, const char * src)
 243 {
 244   int i = 0, j = 0;
 245   while (src[i] && j < destsize-1) {
 246     int i2 = (const char *)_mbsinc((const unsigned char *)src+i) - src;
 247     if (i2 > i+1)
 248       i = i2; // Ignore multibyte chars
 249     else {
 250       if ('A' <= src[i] && src[i] <= 'Z')
 251         dest[j++] = src[i]; // "Pacific Standard Time" => "PST"
 252       i++;
 253     }
 254   }
 255   if (j < 2)
 256     j = 0;
 257   dest[j] = 0;
 258   return dest;
 259 }
 260 #endif // _WIN32
 261
 262 // This value follows the peripheral device type value as defined in
 263 // SCSI Primary Commands, ANSI INCITS 301:1997.  It is also used in
 264 // the ATA standard for packet devices to define the device type.
 265 const char *packetdevicetype(int type){
 266   if (type<0x10)
 267     return packet_types[type];
 268
 269   if (type<0x20)
 270     return "Reserved";
 271
 272   return "Unknown";
 273 }
 274
 275 // Runtime check of byte ordering, throws if different from isbigendian().
 276 static void check_endianness()
 277 {
 278   union {
 279     // Force compile error if int type is not 32bit.
 280     unsigned char c[sizeof(unsigned) == 4 ? 4 : -1];
 281     unsigned i;
 282   } x = {{1,2,3,4}};
 283
 284   int big = -1;
 285   switch (x.i) {
 286     case 0x01020304: big = 1; break;
 287     case 0x04030201: big = 0; break;
 288   }
 289
 290   if (big != (isbigendian() ? 1 : 0))
 291     throw std::logic_error("CPU endianness does not match compile time test");
 292 }
 293
 294 // Utility function prints date and time and timezone into a character
 295 // buffer of length>=64.  All the fuss is needed to get the right
 296 // timezone info (sigh).
 297 void dateandtimezoneepoch(char *buffer, time_t tval){
 298   struct tm *tmval;
 299   const char *timezonename;
 300   char datebuffer[DATEANDEPOCHLEN];
 301   int lenm1;
 302
 303   FixGlibcTimeZoneBug();
 304
 305   // Get the time structure.  We need this to determine if we are in
 306   // daylight savings time or not.
 307   tmval=localtime(&tval);
 308
 309   // Convert to an ASCII string, put in datebuffer
 310   // same as: asctime_r(tmval, datebuffer);
 311   strncpy(datebuffer, asctime(tmval), DATEANDEPOCHLEN);
 312   datebuffer[DATEANDEPOCHLEN-1]='\0';
 313
 314   // Remove newline
 315   lenm1=strlen(datebuffer)-1;
 316   datebuffer[lenm1>=0?lenm1:0]='\0';
 317
 318   // correct timezone name
 319   if (tmval->tm_isdst==0)
 320     // standard time zone
 321     timezonename=tzname[0];
 322   else if (tmval->tm_isdst>0)
 323     // daylight savings in effect
 324     timezonename=tzname[1];
 325   else
 326     // unable to determine if daylight savings in effect
 327     timezonename="";
 328
 329 #ifdef _WIN32
 330   // Fix long non-ascii timezone names
 331     // cppcheck-suppress variableScope
 332   char tzfixbuf[6+1] = "";
 333   if (!getenv("TZ"))
 334     timezonename=fixtzname(tzfixbuf, sizeof(tzfixbuf), timezonename);
 335 #endif
 336
 337   // Finally put the information into the buffer as needed.
 338   snprintf(buffer, DATEANDEPOCHLEN, "%s %s", datebuffer, timezonename);
 339
 340   return;
 341 }
 342
 343 // Date and timezone gets printed into string pointed to by buffer
 344 void dateandtimezone(char *buffer){
 345
 346   // Get the epoch (time in seconds since Jan 1 1970)
 347   time_t tval=time(NULL);
 348
 349   dateandtimezoneepoch(buffer, tval);
 350   return;
 351 }
 352
 353 // A replacement for perror() that sends output to our choice of
 354 // printing. If errno not set then just print message.
 355 void syserror(const char *message){
 356
 357   if (errno) {
 358     // Get the correct system error message:
 359     const char *errormessage=strerror(errno);
 360
 361     // Check that caller has handed a sensible string, and provide
 362     // appropriate output. See perrror(3) man page to understand better.
 363     if (message && *message)
 364       pout("%s: %s\n",message, errormessage);
 365     else
 366       pout("%s\n",errormessage);
 367   }
 368   else if (message && *message)
 369     pout("%s\n",message);
 370
 371   return;
 372 }
 373
 374 // Check regular expression for non-portable features.
 375 //
 376 // POSIX extended regular expressions interpret unmatched ')' ordinary:
 377 // "The close-parenthesis shall be considered special in this context
 378 //  only if matched with a preceding open-parenthesis."
 379 //
 380 // GNU libc and BSD libc support unmatched ')', Cygwin reports an error.
 381 //
 382 // POSIX extended regular expressions do not define empty subexpressions:
 383 // "A vertical-line appearing first or last in an ERE, or immediately following
 384 //  a vertical-line or a left-parenthesis, or immediately preceding a
 385 //  right-parenthesis, produces undefined results."
 386 //
 387 // GNU libc and Cygwin support empty subexpressions, BSD libc reports an error.
 388 //
 389 static const char * check_regex(const char * pattern)
 390 {
 391   int level = 0;
 392   char c;
 393
 394   for (int i = 0; (c = pattern[i]); i++) {
 395     // Skip "\x"
 396     if (c == '\\') {
 397       if (!pattern[++i])
 398         break;
 399       continue;
 400     }
 401
 402     // Skip "[...]"
 403     if (c == '[') {
 404       if (pattern[++i] == '^')
 405         i++;
 406       if (!pattern[i++])
 407         break;
 408       while ((c = pattern[i]) && c != ']')
 409         i++;
 410       if (!c)
 411         break;
 412       continue;
 413     }
 414
 415     // Check "(...)" nesting
 416     if (c == '(')
 417       level++;
 418     else if (c == ')' && --level < 0)
 419       return "Unmatched ')'";
 420
 421     // Check for leading/trailing '|' or "||", "|)", "|$", "(|", "^|"
 422     char c1;
 423     if (   (c == '|' && (   i == 0 || !(c1 = pattern[i+1])
 424                           || c1 == '|' || c1 == ')' || c1 == '$'))
 425         || ((c == '(' || c == '^') && pattern[i+1] == '|')       )
 426       return "Empty '|' subexpression";
 427   }
 428
 429   return (const char *)0;
 430 }
 431
 432 // Wrapper class for regex(3)
 433
 434 regular_expression::regular_expression()
 435 : m_flags(0)
 436 {
 437   memset(&m_regex_buf, 0, sizeof(m_regex_buf));
 438 }
 439
 440 regular_expression::regular_expression(const char * pattern, int flags,
 441                                        bool throw_on_error /*= true*/)
 442 {
 443   memset(&m_regex_buf, 0, sizeof(m_regex_buf));
 444   if (!compile(pattern, flags) && throw_on_error)
 445     throw std::runtime_error(strprintf(
 446       "error in regular expression \"%s\": %s",
 447       m_pattern.c_str(), m_errmsg.c_str()));
 448 }
 449
 450 regular_expression::~regular_expression()
 451 {
 452   free_buf();
 453 }
 454
 455 regular_expression::regular_expression(const regular_expression & x)
 456 {
 457   memset(&m_regex_buf, 0, sizeof(m_regex_buf));
 458   copy(x);
 459 }
 460
 461 regular_expression & regular_expression::operator=(const regular_expression & x)
 462 {
 463   free_buf();
 464   copy(x);
 465   return *this;
 466 }
 467
 468 void regular_expression::free_buf()
 469 {
 470   if (nonempty(&m_regex_buf, sizeof(m_regex_buf))) {
 471     regfree(&m_regex_buf);
 472     memset(&m_regex_buf, 0, sizeof(m_regex_buf));
 473   }
 474 }
 475
 476 void regular_expression::copy(const regular_expression & x)
 477 {
 478   m_pattern = x.m_pattern;
 479   m_flags = x.m_flags;
 480   m_errmsg = x.m_errmsg;
 481
 482   if (!m_pattern.empty() && m_errmsg.empty()) {
 483     // There is no POSIX compiled-regex-copy command.
 484     if (!compile())
 485       throw std::runtime_error(strprintf(
 486         "Unable to recompile regular expression \"%s\": %s",
 487         m_pattern.c_str(), m_errmsg.c_str()));
 488   }
 489 }
 490
 491 bool regular_expression::compile(const char * pattern, int flags)
 492 {
 493   free_buf();
 494   m_pattern = pattern;
 495   m_flags = flags;
 496   return compile();
 497 }
 498
 499 bool regular_expression::compile()
 500 {
 501   int errcode = regcomp(&m_regex_buf, m_pattern.c_str(), m_flags);
 502   if (errcode) {
 503     char errmsg[512];
 504     regerror(errcode, &m_regex_buf, errmsg, sizeof(errmsg));
 505     m_errmsg = errmsg;
 506     free_buf();
 507     return false;
 508   }
 509
 510   const char * errmsg = check_regex(m_pattern.c_str());
 511   if (errmsg) {
 512     m_errmsg = errmsg;
 513     free_buf();
 514     return false;
 515   }
 516
 517   m_errmsg.clear();
 518   return true;
 519 }
 520
 521 #ifndef HAVE_STRTOULL
 522 // Replacement for missing strtoull() (Linux with libc < 6, MSVC)
 523 // Functionality reduced to requirements of smartd and split_selective_arg().
 524
 525 uint64_t strtoull(const char * p, char * * endp, int base)
 526 {
 527   uint64_t result, maxres;
 528   int i = 0;
 529   char c = p[i++];
 530
 531   if (!base) {
 532     if (c == '0') {
 533       if (p[i] == 'x' || p[i] == 'X') {
 534         base = 16; i++;
 535       }
 536       else
 537         base = 8;
 538       c = p[i++];
 539     }
 540     else
 541       base = 10;
 542   }
 543
 544   result = 0;
 545   maxres = ~(uint64_t)0 / (unsigned)base;
 546   for (;;) {
 547     unsigned digit;
 548     if ('0' <= c && c <= '9')
 549       digit = c - '0';
 550     else if ('A' <= c && c <= 'Z')
 551       digit = c - 'A' + 10;
 552     else if ('a' <= c && c <= 'z')
 553       digit = c - 'a' + 10;
 554     else
 555       break;
 556     if (digit >= (unsigned)base)
 557       break;
 558     if (!(   result < maxres
 559           || (result == maxres && digit <= ~(uint64_t)0 % (unsigned)base))) {
 560       result = ~(uint64_t)0; errno = ERANGE; // return on overflow
 561       break;
 562     }
 563     result = result * (unsigned)base + digit;
 564     c = p[i++];
 565   }
 566   if (endp)
 567     *endp = (char *)p + i - 1;
 568   return result;
 569 }
 570 #endif // HAVE_STRTOLL
 571
 572 // Splits an argument to the -t option that is assumed to be of the form
 573 // "selective,%lld-%lld" (prefixes of "0" (for octal) and "0x"/"0X" (for hex)
 574 // are allowed).  The first long long int is assigned to *start and the second
 575 // to *stop.  Returns zero if successful and non-zero otherwise.
 576 int split_selective_arg(char *s, uint64_t *start,
 577                         uint64_t *stop, int *mode)
 578 {
 579   char *tailptr;
 580   if (!(s = strchr(s, ',')))
 581     return 1;
 582   bool add = false;
 583   if (!isdigit((int)(*++s))) {
 584     *start = *stop = 0;
 585     if (!strncmp(s, "redo", 4))
 586       *mode = SEL_REDO;
 587     else if (!strncmp(s, "next", 4))
 588       *mode = SEL_NEXT;
 589     else if (!strncmp(s, "cont", 4))
 590       *mode = SEL_CONT;
 591     else
 592       return 1;
 593     s += 4;
 594     if (!*s)
 595       return 0;
 596     if (*s != '+')
 597       return 1;
 598   }
 599   else {
 600     *mode = SEL_RANGE;
 601     errno = 0;
 602     // Last argument to strtoull (the base) is 0 meaning that decimal is assumed
 603     // unless prefixes of "0" (for octal) or "0x"/"0X" (for hex) are used.
 604     *start = strtoull(s, &tailptr, 0);
 605     s = tailptr;
 606     add = (*s == '+');
 607     if (!(!errno && (add || *s == '-')))
 608       return 1;
 609     if (!strcmp(s, "-max")) {
 610       *stop = ~(uint64_t)0; // replaced by max LBA later
 611       return 0;
 612     }
 613   }
 614
 615   errno = 0;
 616   *stop = strtoull(s+1, &tailptr, 0);
 617   if (errno || *tailptr != '\0')
 618     return 1;
 619   if (add) {
 620     if (*stop > 0)
 621       (*stop)--;
 622     *stop += *start; // -t select,N+M => -t select,N,(N+M-1)
 623   }
 624   return 0;
 625 }
 626
 627 // Returns true if region of memory contains non-zero entries
 628 bool nonempty(const void * data, int size)
 629 {
 630   for (int i = 0; i < size; i++)
 631     if (((const unsigned char *)data)[i])
 632       return true;
 633   return false;
 634 }
 635
 636 // Copy not null terminated char array to null terminated string.
 637 // Replace non-ascii characters.  Remove leading and trailing blanks.
 638 const char * format_char_array(char * str, int strsize, const char * chr, int chrsize)
 639 {
 640   int b = 0;
 641   while (b < chrsize && chr[b] == ' ')
 642     b++;
 643   int n = 0;
 644   while (b+n < chrsize && chr[b+n])
 645     n++;
 646   while (n > 0 && chr[b+n-1] == ' ')
 647     n--;
 648
 649   if (n >= strsize)
 650     n = strsize-1;
 651
 652   for (int i = 0; i < n; i++) {
 653     char c = chr[b+i];
 654     str[i] = (' ' <= c && c <= '~' ? c : '?');
 655   }
 656
 657   str[n] = 0;
 658   return str;
 659 }
 660
 661 // Format integer with thousands separator
 662 const char * format_with_thousands_sep(char * str, int strsize, uint64_t val,
 663                                        const char * thousands_sep /* = 0 */)
 664 {
 665   if (!thousands_sep) {
 666     thousands_sep = ",";
 667 #ifdef HAVE_LOCALE_H
 668     setlocale(LC_ALL, "");
 669     const struct lconv * currentlocale = localeconv();
 670     if (*(currentlocale->thousands_sep))
 671       thousands_sep = currentlocale->thousands_sep;
 672 #endif
 673   }
 674
 675   char num[64];
 676   snprintf(num, sizeof(num), "%" PRIu64, val);
 677   int numlen = strlen(num);
 678
 679   int i = 0, j = 0;
 680   do
 681     str[j++] = num[i++];
 682   while (i < numlen && (numlen - i) % 3 != 0 && j < strsize-1);
 683   str[j] = 0;
 684
 685   while (i < numlen && j < strsize-1) {
 686     j += snprintf(str+j, strsize-j, "%s%.3s", thousands_sep, num+i);
 687     i += 3;
 688   }
 689
 690   return str;
 691 }
 692
 693 // Format capacity with SI prefixes
 694 const char * format_capacity(char * str, int strsize, uint64_t val,
 695                              const char * decimal_point /* = 0 */)
 696 {
 697   if (!decimal_point) {
 698     decimal_point = ".";
 699 #ifdef HAVE_LOCALE_H
 700     setlocale(LC_ALL, "");
 701     const struct lconv * currentlocale = localeconv();
 702     if (*(currentlocale->decimal_point))
 703       decimal_point = currentlocale->decimal_point;
 704 #endif
 705   }
 706
 707   const unsigned factor = 1000; // 1024 for KiB,MiB,...
 708   static const char prefixes[] = " KMGTP";
 709
 710   // Find d with val in [d, d*factor)
 711   unsigned i = 0;
 712   uint64_t d = 1;
 713   for (uint64_t d2 = d * factor; val >= d2; d2 *= factor) {
 714     d = d2;
 715     if (++i >= sizeof(prefixes)-2)
 716       break;
 717   }
 718
 719   // Print 3 digits
 720   uint64_t n = val / d;
 721   if (i == 0)
 722     snprintf(str, strsize, "%u B", (unsigned)n);
 723   else if (n >= 100) // "123 xB"
 724     snprintf(str, strsize, "%" PRIu64 " %cB", n, prefixes[i]);
 725   else if (n >= 10)  // "12.3 xB"
 726     snprintf(str, strsize, "%" PRIu64 "%s%u %cB", n, decimal_point,
 727         (unsigned)(((val % d) * 10) / d), prefixes[i]);
 728   else               // "1.23 xB"
 729     snprintf(str, strsize, "%" PRIu64 "%s%02u %cB", n, decimal_point,
 730         (unsigned)(((val % d) * 100) / d), prefixes[i]);
 731
 732   return str;
 733 }
 734
 735 // return (v)sprintf() formatted std::string
 736
 737 std::string vstrprintf(const char * fmt, va_list ap)
 738 {
 739   char buf[512];
 740   vsnprintf(buf, sizeof(buf), fmt, ap);
 741   buf[sizeof(buf)-1] = 0;
 742   return buf;
 743 }
 744
 745 std::string strprintf(const char * fmt, ...)
 746 {
 747   va_list ap; va_start(ap, fmt);
 748   std::string str = vstrprintf(fmt, ap);
 749   va_end(ap);
 750   return str;
 751 }
 752
 753
 754 #ifndef HAVE_WORKING_SNPRINTF
 755 // Some versions of (v)snprintf() don't append null char (MSVCRT.DLL),
 756 // and/or return -1 on output truncation (glibc <= 2.0.6).
 757 // Below are sane replacements substituted by #define in utility.h.
 758
 759 #undef vsnprintf
 760 #if defined(_WIN32) && defined(_MSC_VER)
 761 #define vsnprintf _vsnprintf
 762 #endif
 763
 764 int safe_vsnprintf(char *buf, int size, const char *fmt, va_list ap)
 765 {
 766   int i;
 767   if (size <= 0)
 768     return 0;
 769   i = vsnprintf(buf, size, fmt, ap);
 770   if (0 <= i && i < size)
 771     return i;
 772   buf[size-1] = 0;
 773   return strlen(buf); // Note: cannot detect for overflow, not necessary here.
 774 }
 775
 776 int safe_snprintf(char *buf, int size, const char *fmt, ...)
 777 {
 778   int i; va_list ap;
 779   va_start(ap, fmt);
 780   i = safe_vsnprintf(buf, size, fmt, ap);
 781   va_end(ap);
 782   return i;
 783 }
 784
 785 #else // HAVE_WORKING_SNPRINTF
 786
 787 static void check_snprintf()
 788 {
 789   char buf[] =              "ABCDEFGHI";
 790   int n1 = snprintf(buf, 8, "123456789");
 791   int n2 = snprintf(buf, 0, "X");
 792   if (!(!strcmp(buf, "1234567") && n1 == 9 && n2 == 1))
 793     throw std::logic_error("Function snprintf() does not conform to C99,\n"
 794                            "please contact " PACKAGE_BUGREPORT);
 795 }
 796
 797 #endif // HAVE_WORKING_SNPRINTF
 798
 799 // Runtime check of ./configure result, throws on error.
 800 void check_config()
 801 {
 802   check_endianness();
 803 #ifdef HAVE_WORKING_SNPRINTF
 804   check_snprintf();
 805 #endif
 806 }