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1.1 ! root 1: /* ! 2: * snprintf.c - a portable implementation of snprintf ! 3: * ! 4: * AUTHOR ! 5: * Mark Martinec <[email protected]>, April 1999. ! 6: * ! 7: * Copyright 1999, Mark Martinec. All rights reserved. ! 8: * ! 9: * TERMS AND CONDITIONS ! 10: * This program is free software; you can redistribute it and/or modify ! 11: * it under the terms of the "Frontier Artistic License" which comes ! 12: * with this Kit. ! 13: * ! 14: * This program is distributed in the hope that it will be useful, ! 15: * but WITHOUT ANY WARRANTY; without even the implied warranty ! 16: * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ! 17: * See the Frontier Artistic License for more details. ! 18: * ! 19: * You should have received a copy of the Frontier Artistic License ! 20: * with this Kit in the file named LICENSE.txt . ! 21: * If not, I'll be glad to provide one. ! 22: * ! 23: * FEATURES ! 24: * - careful adherence to specs regarding flags, field width and precision; ! 25: * - good performance for large string handling (large format, large ! 26: * argument or large paddings). Performance is similar to system's sprintf ! 27: * and in several cases significantly better (make sure you compile with ! 28: * optimizations turned on, tell the compiler the code is strict ANSI ! 29: * if necessary to give it more freedom for optimizations); ! 30: * - return value semantics per ISO/IEC 9899:1999 ("ISO C99"); ! 31: * - written in standard ISO/ANSI C - requires an ANSI C compiler. ! 32: * ! 33: * SUPPORTED CONVERSION SPECIFIERS AND DATA TYPES ! 34: * ! 35: * This snprintf only supports the following conversion specifiers: ! 36: * s, c, d, u, o, x, X, p (and synonyms: i, D, U, O - see below) ! 37: * with flags: '-', '+', ' ', '0' and '#'. ! 38: * An asterisk is supported for field width as well as precision. ! 39: * ! 40: * Length modifiers 'h' (short int), 'l' (long int), ! 41: * and 'll' (long long int) are supported. ! 42: * NOTE: ! 43: * If macro SNPRINTF_LONGLONG_SUPPORT is not defined (default) the ! 44: * length modifier 'll' is recognized but treated the same as 'l', ! 45: * which may cause argument value truncation! Defining ! 46: * SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also ! 47: * handles length modifier 'll'. long long int is a language extension ! 48: * which may not be portable. ! 49: * ! 50: * Conversion of numeric data (conversion specifiers d, u, o, x, X, p) ! 51: * with length modifiers (none or h, l, ll) is left to the system routine ! 52: * sprintf, but all handling of flags, field width and precision as well as ! 53: * c and s conversions is done very carefully by this portable routine. ! 54: * If a string precision (truncation) is specified (e.g. %.8s) it is ! 55: * guaranteed the string beyond the specified precision will not be referenced. ! 56: * ! 57: * Length modifiers h, l and ll are ignored for c and s conversions (data ! 58: * types wint_t and wchar_t are not supported). ! 59: * ! 60: * The following common synonyms for conversion characters are supported: ! 61: * - i is a synonym for d ! 62: * - D is a synonym for ld, explicit length modifiers are ignored ! 63: * - U is a synonym for lu, explicit length modifiers are ignored ! 64: * - O is a synonym for lo, explicit length modifiers are ignored ! 65: * The D, O and U conversion characters are nonstandard, they are supported ! 66: * for backward compatibility only, and should not be used for new code. ! 67: * ! 68: * The following is specifically NOT supported: ! 69: * - flag ' (thousands' grouping character) is recognized but ignored ! 70: * - numeric conversion specifiers: f, e, E, g, G and synonym F, ! 71: * as well as the new a and A conversion specifiers ! 72: * - length modifier 'L' (long double) and 'q' (quad - use 'll' instead) ! 73: * - wide character/string conversions: lc, ls, and nonstandard ! 74: * synonyms C and S ! 75: * - writeback of converted string length: conversion character n ! 76: * - the n$ specification for direct reference to n-th argument ! 77: * - locales ! 78: * ! 79: * It is permitted for str_m to be zero, and it is permitted to specify NULL ! 80: * pointer for resulting string argument if str_m is zero (as per ISO C99). ! 81: * ! 82: * The return value is the number of characters which would be generated ! 83: * for the given input, excluding the trailing null. If this value ! 84: * is greater or equal to str_m, not all characters from the result ! 85: * have been stored in str, output bytes beyond the (str_m-1) -th character ! 86: * are discarded. If str_m is greater than zero it is guaranteed ! 87: * the resulting string will be null-terminated. ! 88: * ! 89: * NOTE that this matches the ISO C99, OpenBSD, and GNU C library 2.1, ! 90: * but is different from some older and vendor implementations, ! 91: * and is also different from XPG, XSH5, SUSv2 specifications. ! 92: * For historical discussion on changes in the semantics and standards ! 93: * of snprintf see printf(3) man page in the Linux programmers manual. ! 94: * ! 95: * Routines asprintf and vasprintf return a pointer (in the ptr argument) ! 96: * to a buffer sufficiently large to hold the resulting string. This pointer ! 97: * should be passed to free(3) to release the allocated storage when it is ! 98: * no longer needed. If sufficient space cannot be allocated, these functions ! 99: * will return -1 and set ptr to be a NULL pointer. These two routines are a ! 100: * GNU C library extensions (glibc). ! 101: * ! 102: * Routines asnprintf and vasnprintf are similar to asprintf and vasprintf, ! 103: * yet, like snprintf and vsnprintf counterparts, will write at most str_m-1 ! 104: * characters into the allocated output string, the last character in the ! 105: * allocated buffer then gets the terminating null. If the formatted string ! 106: * length (the return value) is greater than or equal to the str_m argument, ! 107: * the resulting string was truncated and some of the formatted characters ! 108: * were discarded. These routines present a handy way to limit the amount ! 109: * of allocated memory to some sane value. ! 110: * ! 111: * AVAILABILITY ! 112: * http://www.ijs.si/software/snprintf/ ! 113: * ! 114: * REVISION HISTORY ! 115: * 1999-04 V0.9 Mark Martinec ! 116: * - initial version, some modifications after comparing printf ! 117: * man pages for Digital Unix 4.0, Solaris 2.6 and HPUX 10, ! 118: * and checking how Perl handles sprintf (differently!); ! 119: * 1999-04-09 V1.0 Mark Martinec <[email protected]> ! 120: * - added main test program, fixed remaining inconsistencies, ! 121: * added optional (long long int) support; ! 122: * 1999-04-12 V1.1 Mark Martinec <[email protected]> ! 123: * - support the 'p' conversion (pointer to void); ! 124: * - if a string precision is specified ! 125: * make sure the string beyond the specified precision ! 126: * will not be referenced (e.g. by strlen); ! 127: * 1999-04-13 V1.2 Mark Martinec <[email protected]> ! 128: * - support synonyms %D=%ld, %U=%lu, %O=%lo; ! 129: * - speed up the case of long format string with few conversions; ! 130: * 1999-06-30 V1.3 Mark Martinec <[email protected]> ! 131: * - fixed runaway loop (eventually crashing when str_l wraps ! 132: * beyond 2^31) while copying format string without ! 133: * conversion specifiers to a buffer that is too short ! 134: * (thanks to Edwin Young <[email protected]> for ! 135: * spotting the problem); ! 136: * - added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR) ! 137: * to snprintf.h ! 138: * 2000-02-14 V2.0 (never released) Mark Martinec <[email protected]> ! 139: * - relaxed license terms: The Artistic License now applies. ! 140: * You may still apply the GNU GENERAL PUBLIC LICENSE ! 141: * as was distributed with previous versions, if you prefer; ! 142: * - changed REVISION HISTORY dates to use ISO 8601 date format; ! 143: * - added vsnprintf (patch also independently proposed by ! 144: * Caolan McNamara 2000-05-04, and Keith M Willenson 2000-06-01) ! 145: * 2000-06-27 V2.1 Mark Martinec <[email protected]> ! 146: * - removed POSIX check for str_m<1; value 0 for str_m is ! 147: * allowed by ISO C99 (and GNU C library 2.1) - (pointed out ! 148: * on 2000-05-04 by Caolan McNamara, caolan@ csn dot ul dot ie). ! 149: * Besides relaxed license this change in standards adherence ! 150: * is the main reason to bump up the major version number; ! 151: * - added nonstandard routines asnprintf, vasnprintf, asprintf, ! 152: * vasprintf that dynamically allocate storage for the ! 153: * resulting string; these routines are not compiled by default, ! 154: * see comments where NEED_V?ASN?PRINTF macros are defined; ! 155: * - autoconf contributed by Caolan McNamara ! 156: * 2000-10-06 V2.2 Mark Martinec <[email protected]> ! 157: * - BUG FIX: the %c conversion used a temporary variable ! 158: * that was no longer in scope when referenced, ! 159: * possibly causing incorrect resulting character; ! 160: * - BUG FIX: make precision and minimal field width unsigned ! 161: * to handle huge values (2^31 <= n < 2^32) correctly; ! 162: * also be more careful in the use of signed/unsigned/size_t ! 163: * internal variables - probably more careful than many ! 164: * vendor implementations, but there may still be a case ! 165: * where huge values of str_m, precision or minimal field ! 166: * could cause incorrect behaviour; ! 167: * - use separate variables for signed/unsigned arguments, ! 168: * and for short/int, long, and long long argument lengths ! 169: * to avoid possible incompatibilities on certain ! 170: * computer architectures. Also use separate variable ! 171: * arg_sign to hold sign of a numeric argument, ! 172: * to make code more transparent; ! 173: * - some fiddling with zero padding and "0x" to make it ! 174: * Linux compatible; ! 175: * - systematically use macros fast_memcpy and fast_memset ! 176: * instead of case-by-case hand optimization; determine some ! 177: * breakeven string lengths for different architectures; ! 178: * - terminology change: 'format' -> 'conversion specifier', ! 179: * 'C9x' -> 'ISO/IEC 9899:1999 ("ISO C99")', ! 180: * 'alternative form' -> 'alternate form', ! 181: * 'data type modifier' -> 'length modifier'; ! 182: * - several comments rephrased and new ones added; ! 183: * - make compiler not complain about 'credits' defined but ! 184: * not used; ! 185: */ ! 186: ! 187: ! 188: /* Define HAVE_SNPRINTF if your system already has snprintf and vsnprintf. ! 189: * ! 190: * If HAVE_SNPRINTF is defined this module will not produce code for ! 191: * snprintf and vsnprintf, unless PREFER_PORTABLE_SNPRINTF is defined as well, ! 192: * causing this portable version of snprintf to be called portable_snprintf ! 193: * (and portable_vsnprintf). ! 194: */ ! 195: /* #define HAVE_SNPRINTF */ ! 196: ! 197: /* Define PREFER_PORTABLE_SNPRINTF if your system does have snprintf and ! 198: * vsnprintf but you would prefer to use the portable routine(s) instead. ! 199: * In this case the portable routine is declared as portable_snprintf ! 200: * (and portable_vsnprintf) and a macro 'snprintf' (and 'vsnprintf') ! 201: * is defined to expand to 'portable_v?snprintf' - see file snprintf.h . ! 202: * Defining this macro is only useful if HAVE_SNPRINTF is also defined, ! 203: * but does does no harm if defined nevertheless. ! 204: */ ! 205: /* #define PREFER_PORTABLE_SNPRINTF */ ! 206: ! 207: /* Define SNPRINTF_LONGLONG_SUPPORT if you want to support ! 208: * data type (long long int) and length modifier 'll' (e.g. %lld). ! 209: * If undefined, 'll' is recognized but treated as a single 'l'. ! 210: * ! 211: * If the system's sprintf does not handle 'll' ! 212: * the SNPRINTF_LONGLONG_SUPPORT must not be defined! ! 213: * ! 214: * This is off by default as (long long int) is a language extension. ! 215: */ ! 216: /* #define SNPRINTF_LONGLONG_SUPPORT */ ! 217: ! 218: /* Define NEED_SNPRINTF_ONLY if you only need snprintf, and not vsnprintf. ! 219: * If NEED_SNPRINTF_ONLY is defined, the snprintf will be defined directly, ! 220: * otherwise both snprintf and vsnprintf routines will be defined ! 221: * and snprintf will be a simple wrapper around vsnprintf, at the expense ! 222: * of an extra procedure call. ! 223: */ ! 224: /* #define NEED_SNPRINTF_ONLY */ ! 225: ! 226: /* Define NEED_V?ASN?PRINTF macros if you need library extension ! 227: * routines asprintf, vasprintf, asnprintf, vasnprintf respectively, ! 228: * and your system library does not provide them. They are all small ! 229: * wrapper routines around portable_vsnprintf. Defining any of the four ! 230: * NEED_V?ASN?PRINTF macros automatically turns off NEED_SNPRINTF_ONLY ! 231: * and turns on PREFER_PORTABLE_SNPRINTF. ! 232: * ! 233: * Watch for name conflicts with the system library if these routines ! 234: * are already present there. ! 235: * ! 236: * NOTE: vasprintf and vasnprintf routines need va_copy() from stdarg.h, as ! 237: * specified by C99, to be able to traverse the same list of arguments twice. ! 238: * I don't know of any other standard and portable way of achieving the same. ! 239: * With some versions of gcc you may use __va_copy(). You might even get away ! 240: * with "ap2 = ap", in this case you must not call va_end(ap2) ! ! 241: * #define va_copy(ap2,ap) ap2 = ap ! 242: */ ! 243: /* #define NEED_ASPRINTF */ ! 244: /* #define NEED_ASNPRINTF */ ! 245: /* #define NEED_VASPRINTF */ ! 246: /* #define NEED_VASNPRINTF */ ! 247: ! 248: ! 249: /* Define the following macros if desired: ! 250: * SOLARIS_COMPATIBLE, SOLARIS_BUG_COMPATIBLE, ! 251: * HPUX_COMPATIBLE, HPUX_BUG_COMPATIBLE, LINUX_COMPATIBLE, ! 252: * DIGITAL_UNIX_COMPATIBLE, DIGITAL_UNIX_BUG_COMPATIBLE, ! 253: * PERL_COMPATIBLE, PERL_BUG_COMPATIBLE, ! 254: * ! 255: * - For portable applications it is best not to rely on peculiarities ! 256: * of a given implementation so it may be best not to define any ! 257: * of the macros that select compatibility and to avoid features ! 258: * that vary among the systems. ! 259: * ! 260: * - Selecting compatibility with more than one operating system ! 261: * is not strictly forbidden but is not recommended. ! 262: * ! 263: * - 'x'_BUG_COMPATIBLE implies 'x'_COMPATIBLE . ! 264: * ! 265: * - 'x'_COMPATIBLE refers to (and enables) a behaviour that is ! 266: * documented in a sprintf man page on a given operating system ! 267: * and actually adhered to by the system's sprintf (but not on ! 268: * most other operating systems). It may also refer to and enable ! 269: * a behaviour that is declared 'undefined' or 'implementation specific' ! 270: * in the man page but a given implementation behaves predictably ! 271: * in a certain way. ! 272: * ! 273: * - 'x'_BUG_COMPATIBLE refers to (and enables) a behaviour of system's sprintf ! 274: * that contradicts the sprintf man page on the same operating system. ! 275: * ! 276: * - I do not claim that the 'x'_COMPATIBLE and 'x'_BUG_COMPATIBLE ! 277: * conditionals take into account all idiosyncrasies of a particular ! 278: * implementation, there may be other incompatibilities. ! 279: */ ! 280: ! 281: ! 282: ! 283: /* ============================================= */ ! 284: /* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */ ! 285: /* ============================================= */ ! 286: ! 287: #define PORTABLE_SNPRINTF_VERSION_MAJOR 2 ! 288: #define PORTABLE_SNPRINTF_VERSION_MINOR 2 ! 289: ! 290: #if defined(NEED_ASPRINTF) || defined(NEED_ASNPRINTF) || defined(NEED_VASPRINTF) || defined(NEED_VASNPRINTF) ! 291: # if defined(NEED_SNPRINTF_ONLY) ! 292: # undef NEED_SNPRINTF_ONLY ! 293: # endif ! 294: # if !defined(PREFER_PORTABLE_SNPRINTF) ! 295: # define PREFER_PORTABLE_SNPRINTF ! 296: # endif ! 297: #endif ! 298: ! 299: #if defined(SOLARIS_BUG_COMPATIBLE) && !defined(SOLARIS_COMPATIBLE) ! 300: #define SOLARIS_COMPATIBLE ! 301: #endif ! 302: ! 303: #if defined(HPUX_BUG_COMPATIBLE) && !defined(HPUX_COMPATIBLE) ! 304: #define HPUX_COMPATIBLE ! 305: #endif ! 306: ! 307: #if defined(DIGITAL_UNIX_BUG_COMPATIBLE) && !defined(DIGITAL_UNIX_COMPATIBLE) ! 308: #define DIGITAL_UNIX_COMPATIBLE ! 309: #endif ! 310: ! 311: #if defined(PERL_BUG_COMPATIBLE) && !defined(PERL_COMPATIBLE) ! 312: #define PERL_COMPATIBLE ! 313: #endif ! 314: ! 315: #if defined(LINUX_BUG_COMPATIBLE) && !defined(LINUX_COMPATIBLE) ! 316: #define LINUX_COMPATIBLE ! 317: #endif ! 318: ! 319: #include <sys/types.h> ! 320: #include <string.h> ! 321: #include <stdlib.h> ! 322: #include <stdio.h> ! 323: #include <stdarg.h> ! 324: #include <assert.h> ! 325: #include <errno.h> ! 326: ! 327: #ifdef isdigit ! 328: #undef isdigit ! 329: #endif ! 330: #define isdigit(c) ((c) >= '0' && (c) <= '9') ! 331: ! 332: /* For copying strings longer or equal to 'breakeven_point' ! 333: * it is more efficient to call memcpy() than to do it inline. ! 334: * The value depends mostly on the processor architecture, ! 335: * but also on the compiler and its optimization capabilities. ! 336: * The value is not critical, some small value greater than zero ! 337: * will be just fine if you don't care to squeeze every drop ! 338: * of performance out of the code. ! 339: * ! 340: * Small values favor memcpy, large values favor inline code. ! 341: */ ! 342: #if defined(__alpha__) || defined(__alpha) ! 343: # define breakeven_point 2 /* AXP (DEC Alpha) - gcc or cc or egcs */ ! 344: #endif ! 345: #if defined(__i386__) || defined(__i386) ! 346: # define breakeven_point 12 /* Intel Pentium/Linux - gcc 2.96 */ ! 347: #endif ! 348: #if defined(__hppa) ! 349: # define breakeven_point 10 /* HP-PA - gcc */ ! 350: #endif ! 351: #if defined(__sparc__) || defined(__sparc) ! 352: # define breakeven_point 33 /* Sun Sparc 5 - gcc 2.8.1 */ ! 353: #endif ! 354: ! 355: /* some other values of possible interest: */ ! 356: /* #define breakeven_point 8 */ /* VAX 4000 - vaxc */ ! 357: /* #define breakeven_point 19 */ /* VAX 4000 - gcc 2.7.0 */ ! 358: ! 359: #ifndef breakeven_point ! 360: # define breakeven_point 6 /* some reasonable one-size-fits-all value */ ! 361: #endif ! 362: ! 363: #define fast_memcpy(d,s,n) \ ! 364: { register size_t nn = (size_t)(n); \ ! 365: if (nn >= breakeven_point) memcpy((d), (s), nn); \ ! 366: else if (nn > 0) { /* proc call overhead is worth only for large strings*/\ ! 367: register char *dd; register const char *ss; \ ! 368: for (ss=(s), dd=(d); nn>0; nn--) *dd++ = *ss++; } } ! 369: ! 370: #define fast_memset(d,c,n) \ ! 371: { register size_t nn = (size_t)(n); \ ! 372: if (nn >= breakeven_point) memset((d), (int)(c), nn); \ ! 373: else if (nn > 0) { /* proc call overhead is worth only for large strings*/\ ! 374: register char *dd; register const int cc=(int)(c); \ ! 375: for (dd=(d); nn>0; nn--) *dd++ = cc; } } ! 376: ! 377: /* prototypes */ ! 378: ! 379: #if defined(NEED_ASPRINTF) ! 380: int asprintf (char **ptr, const char *fmt, /*args*/ ...); ! 381: #endif ! 382: #if defined(NEED_VASPRINTF) ! 383: int vasprintf (char **ptr, const char *fmt, va_list ap); ! 384: #endif ! 385: #if defined(NEED_ASNPRINTF) ! 386: int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...); ! 387: #endif ! 388: #if defined(NEED_VASNPRINTF) ! 389: int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap); ! 390: #endif ! 391: ! 392: #if defined(HAVE_SNPRINTF) ! 393: /* declare our portable snprintf routine under name portable_snprintf */ ! 394: /* declare our portable vsnprintf routine under name portable_vsnprintf */ ! 395: #else ! 396: /* declare our portable routines under names snprintf and vsnprintf */ ! 397: #define portable_snprintf snprintf ! 398: #if !defined(NEED_SNPRINTF_ONLY) ! 399: #define portable_vsnprintf vsnprintf ! 400: #endif ! 401: #endif ! 402: ! 403: #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF) ! 404: int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...); ! 405: #if !defined(NEED_SNPRINTF_ONLY) ! 406: int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap); ! 407: #endif ! 408: #endif ! 409: ! 410: /* declarations */ ! 411: ! 412: static char credits[] = "\n\ ! 413: @(#)snprintf.c, v2.2: Mark Martinec, <[email protected]>\n\ ! 414: @(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\ ! 415: @(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n"; ! 416: ! 417: #if defined(NEED_ASPRINTF) ! 418: int asprintf(char **ptr, const char *fmt, /*args*/ ...) { ! 419: va_list ap; ! 420: size_t str_m; ! 421: int str_l; ! 422: ! 423: *ptr = NULL; ! 424: va_start(ap, fmt); /* measure the required size */ ! 425: str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap); ! 426: va_end(ap); ! 427: assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */ ! 428: *ptr = (char *) malloc(str_m = (size_t)str_l + 1); ! 429: if (*ptr == NULL) { errno = ENOMEM; str_l = -1; } ! 430: else { ! 431: int str_l2; ! 432: va_start(ap, fmt); ! 433: str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap); ! 434: va_end(ap); ! 435: assert(str_l2 == str_l); ! 436: } ! 437: return str_l; ! 438: } ! 439: #endif ! 440: ! 441: #if defined(NEED_VASPRINTF) ! 442: int vasprintf(char **ptr, const char *fmt, va_list ap) { ! 443: size_t str_m; ! 444: int str_l; ! 445: ! 446: *ptr = NULL; ! 447: { va_list ap2; ! 448: va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */ ! 449: str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/ ! 450: va_end(ap2); ! 451: } ! 452: assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */ ! 453: *ptr = (char *) malloc(str_m = (size_t)str_l + 1); ! 454: if (*ptr == NULL) { errno = ENOMEM; str_l = -1; } ! 455: else { ! 456: int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap); ! 457: assert(str_l2 == str_l); ! 458: } ! 459: return str_l; ! 460: } ! 461: #endif ! 462: ! 463: #if defined(NEED_ASNPRINTF) ! 464: int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...) { ! 465: va_list ap; ! 466: int str_l; ! 467: ! 468: *ptr = NULL; ! 469: va_start(ap, fmt); /* measure the required size */ ! 470: str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap); ! 471: va_end(ap); ! 472: assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */ ! 473: if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */ ! 474: /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */ ! 475: if (str_m == 0) { /* not interested in resulting string, just return size */ ! 476: } else { ! 477: *ptr = (char *) malloc(str_m); ! 478: if (*ptr == NULL) { errno = ENOMEM; str_l = -1; } ! 479: else { ! 480: int str_l2; ! 481: va_start(ap, fmt); ! 482: str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap); ! 483: va_end(ap); ! 484: assert(str_l2 == str_l); ! 485: } ! 486: } ! 487: return str_l; ! 488: } ! 489: #endif ! 490: ! 491: #if defined(NEED_VASNPRINTF) ! 492: int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap) { ! 493: int str_l; ! 494: ! 495: *ptr = NULL; ! 496: { va_list ap2; ! 497: va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */ ! 498: str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/ ! 499: va_end(ap2); ! 500: } ! 501: assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */ ! 502: if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */ ! 503: /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */ ! 504: if (str_m == 0) { /* not interested in resulting string, just return size */ ! 505: } else { ! 506: *ptr = (char *) malloc(str_m); ! 507: if (*ptr == NULL) { errno = ENOMEM; str_l = -1; } ! 508: else { ! 509: int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap); ! 510: assert(str_l2 == str_l); ! 511: } ! 512: } ! 513: return str_l; ! 514: } ! 515: #endif ! 516: ! 517: /* ! 518: * If the system does have snprintf and the portable routine is not ! 519: * specifically required, this module produces no code for snprintf/vsnprintf. ! 520: */ ! 521: #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF) ! 522: ! 523: #if !defined(NEED_SNPRINTF_ONLY) ! 524: int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) { ! 525: va_list ap; ! 526: int str_l; ! 527: ! 528: va_start(ap, fmt); ! 529: str_l = portable_vsnprintf(str, str_m, fmt, ap); ! 530: va_end(ap); ! 531: return str_l; ! 532: } ! 533: #endif ! 534: ! 535: #if defined(NEED_SNPRINTF_ONLY) ! 536: int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) { ! 537: #else ! 538: int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) { ! 539: #endif ! 540: ! 541: #if defined(NEED_SNPRINTF_ONLY) ! 542: va_list ap; ! 543: #endif ! 544: size_t str_l = 0; ! 545: const char *p = fmt; ! 546: ! 547: /* In contrast with POSIX, the ISO C99 now says ! 548: * that str can be NULL and str_m can be 0. ! 549: * This is more useful than the old: if (str_m < 1) return -1; */ ! 550: ! 551: #if defined(NEED_SNPRINTF_ONLY) ! 552: va_start(ap, fmt); ! 553: #endif ! 554: if (!p) p = ""; ! 555: while (*p) { ! 556: if (*p != '%') { ! 557: /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */ ! 558: /* but the following code achieves better performance for cases ! 559: * where format string is long and contains few conversions */ ! 560: const char *q = strchr(p+1,'%'); ! 561: size_t n = !q ? strlen(p) : (q-p); ! 562: if (str_l < str_m) { ! 563: size_t avail = str_m-str_l; ! 564: fast_memcpy(str+str_l, p, (n>avail?avail:n)); ! 565: } ! 566: p += n; str_l += n; ! 567: } else { ! 568: const char *starting_p; ! 569: size_t min_field_width = 0, precision = 0; ! 570: int zero_padding = 0, precision_specified = 0, justify_left = 0; ! 571: int alternate_form = 0, force_sign = 0; ! 572: int space_for_positive = 1; /* If both the ' ' and '+' flags appear, ! 573: the ' ' flag should be ignored. */ ! 574: char length_modifier = '\0'; /* allowed values: \0, h, l, L */ ! 575: char tmp[32];/* temporary buffer for simple numeric->string conversion */ ! 576: ! 577: const char *str_arg; /* string address in case of string argument */ ! 578: size_t str_arg_l; /* natural field width of arg without padding ! 579: and sign */ ! 580: unsigned char uchar_arg; ! 581: /* unsigned char argument value - only defined for c conversion. ! 582: N.B. standard explicitly states the char argument for ! 583: the c conversion is unsigned */ ! 584: ! 585: size_t number_of_zeros_to_pad = 0; ! 586: /* number of zeros to be inserted for numeric conversions ! 587: as required by the precision or minimal field width */ ! 588: ! 589: size_t zero_padding_insertion_ind = 0; ! 590: /* index into tmp where zero padding is to be inserted */ ! 591: ! 592: char fmt_spec = '\0'; ! 593: /* current conversion specifier character */ ! 594: ! 595: str_arg = credits;/* just to make compiler happy (defined but not used)*/ ! 596: str_arg = NULL; ! 597: starting_p = p; p++; /* skip '%' */ ! 598: /* parse flags */ ! 599: while (*p == '0' || *p == '-' || *p == '+' || ! 600: *p == ' ' || *p == '#' || *p == '\'') { ! 601: switch (*p) { ! 602: case '0': zero_padding = 1; break; ! 603: case '-': justify_left = 1; break; ! 604: case '+': force_sign = 1; space_for_positive = 0; break; ! 605: case ' ': force_sign = 1; ! 606: /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */ ! 607: #ifdef PERL_COMPATIBLE ! 608: /* ... but in Perl the last of ' ' and '+' applies */ ! 609: space_for_positive = 1; ! 610: #endif ! 611: break; ! 612: case '#': alternate_form = 1; break; ! 613: case '\'': break; ! 614: } ! 615: p++; ! 616: } ! 617: /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */ ! 618: ! 619: /* parse field width */ ! 620: if (*p == '*') { ! 621: int j; ! 622: p++; j = va_arg(ap, int); ! 623: if (j >= 0) min_field_width = j; ! 624: else { min_field_width = -j; justify_left = 1; } ! 625: } else if (isdigit((int)(*p))) { ! 626: /* size_t could be wider than unsigned int; ! 627: make sure we treat argument like common implementations do */ ! 628: unsigned int uj = *p++ - '0'; ! 629: while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0'); ! 630: min_field_width = uj; ! 631: } ! 632: /* parse precision */ ! 633: if (*p == '.') { ! 634: p++; precision_specified = 1; ! 635: if (*p == '*') { ! 636: int j = va_arg(ap, int); ! 637: p++; ! 638: if (j >= 0) precision = j; ! 639: else { ! 640: precision_specified = 0; precision = 0; ! 641: /* NOTE: ! 642: * Solaris 2.6 man page claims that in this case the precision ! 643: * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page ! 644: * claim that this case should be treated as unspecified precision, ! 645: * which is what we do here. ! 646: */ ! 647: } ! 648: } else if (isdigit((int)(*p))) { ! 649: /* size_t could be wider than unsigned int; ! 650: make sure we treat argument like common implementations do */ ! 651: unsigned int uj = *p++ - '0'; ! 652: while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0'); ! 653: precision = uj; ! 654: } ! 655: } ! 656: /* parse 'h', 'l' and 'll' length modifiers */ ! 657: if (*p == 'h' || *p == 'l') { ! 658: length_modifier = *p; p++; ! 659: if (length_modifier == 'l' && *p == 'l') { /* double l = long long */ ! 660: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 661: length_modifier = '2'; /* double l encoded as '2' */ ! 662: #else ! 663: length_modifier = 'l'; /* treat it as a single 'l' */ ! 664: #endif ! 665: p++; ! 666: } ! 667: } ! 668: fmt_spec = *p; ! 669: /* common synonyms: */ ! 670: switch (fmt_spec) { ! 671: case 'i': fmt_spec = 'd'; break; ! 672: case 'D': fmt_spec = 'd'; length_modifier = 'l'; break; ! 673: case 'U': fmt_spec = 'u'; length_modifier = 'l'; break; ! 674: case 'O': fmt_spec = 'o'; length_modifier = 'l'; break; ! 675: default: break; ! 676: } ! 677: /* get parameter value, do initial processing */ ! 678: switch (fmt_spec) { ! 679: case '%': /* % behaves similar to 's' regarding flags and field widths */ ! 680: case 'c': /* c behaves similar to 's' regarding flags and field widths */ ! 681: case 's': ! 682: length_modifier = '\0'; /* wint_t and wchar_t not supported */ ! 683: /* the result of zero padding flag with non-numeric conversion specifier*/ ! 684: /* is undefined. Solaris and HPUX 10 does zero padding in this case, */ ! 685: /* Digital Unix and Linux does not. */ ! 686: #if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE) ! 687: zero_padding = 0; /* turn zero padding off for string conversions */ ! 688: #endif ! 689: str_arg_l = 1; ! 690: switch (fmt_spec) { ! 691: case '%': ! 692: str_arg = p; break; ! 693: case 'c': { ! 694: int j = va_arg(ap, int); ! 695: uchar_arg = (unsigned char) j; /* standard demands unsigned char */ ! 696: str_arg = (const char *) &uchar_arg; ! 697: break; ! 698: } ! 699: case 's': ! 700: str_arg = va_arg(ap, const char *); ! 701: if (!str_arg) str_arg_l = 0; ! 702: /* make sure not to address string beyond the specified precision !!! */ ! 703: else if (!precision_specified) str_arg_l = strlen(str_arg); ! 704: /* truncate string if necessary as requested by precision */ ! 705: else if (precision == 0) str_arg_l = 0; ! 706: else { ! 707: /* memchr on HP does not like n > 2^31 !!! */ ! 708: const char *q = memchr(str_arg, '\0', ! 709: precision <= 0x7fffffff ? precision : 0x7fffffff); ! 710: str_arg_l = !q ? precision : (q-str_arg); ! 711: } ! 712: break; ! 713: default: break; ! 714: } ! 715: break; ! 716: case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': { ! 717: /* NOTE: the u, o, x, X and p conversion specifiers imply ! 718: the value is unsigned; d implies a signed value */ ! 719: ! 720: int arg_sign = 0; ! 721: /* 0 if numeric argument is zero (or if pointer is NULL for 'p'), ! 722: +1 if greater than zero (or nonzero for unsigned arguments), ! 723: -1 if negative (unsigned argument is never negative) */ ! 724: ! 725: int int_arg = 0; unsigned int uint_arg = 0; ! 726: /* only defined for length modifier h, or for no length modifiers */ ! 727: ! 728: long int long_arg = 0; unsigned long int ulong_arg = 0; ! 729: /* only defined for length modifier l */ ! 730: ! 731: void *ptr_arg = NULL; ! 732: /* pointer argument value -only defined for p conversion */ ! 733: ! 734: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 735: long long int long_long_arg = 0; ! 736: unsigned long long int ulong_long_arg = 0; ! 737: /* only defined for length modifier ll */ ! 738: #endif ! 739: if (fmt_spec == 'p') { ! 740: /* HPUX 10: An l, h, ll or L before any other conversion character ! 741: * (other than d, i, u, o, x, or X) is ignored. ! 742: * Digital Unix: ! 743: * not specified, but seems to behave as HPUX does. ! 744: * Solaris: If an h, l, or L appears before any other conversion ! 745: * specifier (other than d, i, u, o, x, or X), the behavior ! 746: * is undefined. (Actually %hp converts only 16-bits of address ! 747: * and %llp treats address as 64-bit data which is incompatible ! 748: * with (void *) argument on a 32-bit system). ! 749: */ ! 750: #ifdef SOLARIS_COMPATIBLE ! 751: # ifdef SOLARIS_BUG_COMPATIBLE ! 752: /* keep length modifiers even if it represents 'll' */ ! 753: # else ! 754: if (length_modifier == '2') length_modifier = '\0'; ! 755: # endif ! 756: #else ! 757: length_modifier = '\0'; ! 758: #endif ! 759: ptr_arg = va_arg(ap, void *); ! 760: if (ptr_arg != NULL) arg_sign = 1; ! 761: } else if (fmt_spec == 'd') { /* signed */ ! 762: switch (length_modifier) { ! 763: case '\0': ! 764: case 'h': ! 765: /* It is non-portable to specify a second argument of char or short ! 766: * to va_arg, because arguments seen by the called function ! 767: * are not char or short. C converts char and short arguments ! 768: * to int before passing them to a function. ! 769: */ ! 770: int_arg = va_arg(ap, int); ! 771: if (int_arg > 0) arg_sign = 1; ! 772: else if (int_arg < 0) arg_sign = -1; ! 773: break; ! 774: case 'l': ! 775: long_arg = va_arg(ap, long int); ! 776: if (long_arg > 0) arg_sign = 1; ! 777: else if (long_arg < 0) arg_sign = -1; ! 778: break; ! 779: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 780: case '2': ! 781: long_long_arg = va_arg(ap, long long int); ! 782: if (long_long_arg > 0) arg_sign = 1; ! 783: else if (long_long_arg < 0) arg_sign = -1; ! 784: break; ! 785: #endif ! 786: } ! 787: } else { /* unsigned */ ! 788: switch (length_modifier) { ! 789: case '\0': ! 790: case 'h': ! 791: uint_arg = va_arg(ap, unsigned int); ! 792: if (uint_arg) arg_sign = 1; ! 793: break; ! 794: case 'l': ! 795: ulong_arg = va_arg(ap, unsigned long int); ! 796: if (ulong_arg) arg_sign = 1; ! 797: break; ! 798: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 799: case '2': ! 800: ulong_long_arg = va_arg(ap, unsigned long long int); ! 801: if (ulong_long_arg) arg_sign = 1; ! 802: break; ! 803: #endif ! 804: } ! 805: } ! 806: str_arg = tmp; str_arg_l = 0; ! 807: /* NOTE: ! 808: * For d, i, u, o, x, and X conversions, if precision is specified, ! 809: * the '0' flag should be ignored. This is so with Solaris 2.6, ! 810: * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl. ! 811: */ ! 812: #ifndef PERL_COMPATIBLE ! 813: if (precision_specified) zero_padding = 0; ! 814: #endif ! 815: if (fmt_spec == 'd') { ! 816: if (force_sign && arg_sign >= 0) ! 817: tmp[str_arg_l++] = space_for_positive ? ' ' : '+'; ! 818: /* leave negative numbers for sprintf to handle, ! 819: to avoid handling tricky cases like (short int)(-32768) */ ! 820: #ifdef LINUX_COMPATIBLE ! 821: } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) { ! 822: tmp[str_arg_l++] = space_for_positive ? ' ' : '+'; ! 823: #endif ! 824: } else if (alternate_form) { ! 825: if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') ) ! 826: { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; } ! 827: /* alternate form should have no effect for p conversion, but ... */ ! 828: #ifdef HPUX_COMPATIBLE ! 829: else if (fmt_spec == 'p' ! 830: /* HPUX 10: for an alternate form of p conversion, ! 831: * a nonzero result is prefixed by 0x. */ ! 832: #ifndef HPUX_BUG_COMPATIBLE ! 833: /* Actually it uses 0x prefix even for a zero value. */ ! 834: && arg_sign != 0 ! 835: #endif ! 836: ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; } ! 837: #endif ! 838: } ! 839: zero_padding_insertion_ind = str_arg_l; ! 840: if (!precision_specified) precision = 1; /* default precision is 1 */ ! 841: if (precision == 0 && arg_sign == 0 ! 842: #if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE) ! 843: && fmt_spec != 'p' ! 844: /* HPUX 10 man page claims: With conversion character p the result of ! 845: * converting a zero value with a precision of zero is a null string. ! 846: * Actually HP returns all zeroes, and Linux returns "(nil)". */ ! 847: #endif ! 848: ) { ! 849: /* converted to null string */ ! 850: /* When zero value is formatted with an explicit precision 0, ! 851: the resulting formatted string is empty (d, i, u, o, x, X, p). */ ! 852: } else { ! 853: char f[5]; int f_l = 0; ! 854: f[f_l++] = '%'; /* construct a simple format string for sprintf */ ! 855: if (!length_modifier) { } ! 856: else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; } ! 857: else f[f_l++] = length_modifier; ! 858: f[f_l++] = fmt_spec; f[f_l++] = '\0'; ! 859: if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg); ! 860: else if (fmt_spec == 'd') { /* signed */ ! 861: switch (length_modifier) { ! 862: case '\0': ! 863: case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break; ! 864: case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break; ! 865: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 866: case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break; ! 867: #endif ! 868: } ! 869: } else { /* unsigned */ ! 870: switch (length_modifier) { ! 871: case '\0': ! 872: case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break; ! 873: case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break; ! 874: #ifdef SNPRINTF_LONGLONG_SUPPORT ! 875: case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break; ! 876: #endif ! 877: } ! 878: } ! 879: /* include the optional minus sign and possible "0x" ! 880: in the region before the zero padding insertion point */ ! 881: if (zero_padding_insertion_ind < str_arg_l && ! 882: tmp[zero_padding_insertion_ind] == '-') { ! 883: zero_padding_insertion_ind++; ! 884: } ! 885: if (zero_padding_insertion_ind+1 < str_arg_l && ! 886: tmp[zero_padding_insertion_ind] == '0' && ! 887: (tmp[zero_padding_insertion_ind+1] == 'x' || ! 888: tmp[zero_padding_insertion_ind+1] == 'X') ) { ! 889: zero_padding_insertion_ind += 2; ! 890: } ! 891: } ! 892: { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind; ! 893: if (alternate_form && fmt_spec == 'o' ! 894: #ifdef HPUX_COMPATIBLE /* ("%#.o",0) -> "" */ ! 895: && (str_arg_l > 0) ! 896: #endif ! 897: #ifdef DIGITAL_UNIX_BUG_COMPATIBLE /* ("%#o",0) -> "00" */ ! 898: #else ! 899: /* unless zero is already the first character */ ! 900: && !(zero_padding_insertion_ind < str_arg_l ! 901: && tmp[zero_padding_insertion_ind] == '0') ! 902: #endif ! 903: ) { /* assure leading zero for alternate-form octal numbers */ ! 904: if (!precision_specified || precision < num_of_digits+1) { ! 905: /* precision is increased to force the first character to be zero, ! 906: except if a zero value is formatted with an explicit precision ! 907: of zero */ ! 908: precision = num_of_digits+1; precision_specified = 1; ! 909: } ! 910: } ! 911: /* zero padding to specified precision? */ ! 912: if (num_of_digits < precision) ! 913: number_of_zeros_to_pad = precision - num_of_digits; ! 914: } ! 915: /* zero padding to specified minimal field width? */ ! 916: if (!justify_left && zero_padding) { ! 917: int n = min_field_width - (str_arg_l+number_of_zeros_to_pad); ! 918: if (n > 0) number_of_zeros_to_pad += n; ! 919: } ! 920: break; ! 921: } ! 922: default: /* unrecognized conversion specifier, keep format string as-is*/ ! 923: zero_padding = 0; /* turn zero padding off for non-numeric convers. */ ! 924: #ifndef DIGITAL_UNIX_COMPATIBLE ! 925: justify_left = 1; min_field_width = 0; /* reset flags */ ! 926: #endif ! 927: #if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE) ! 928: /* keep the entire format string unchanged */ ! 929: str_arg = starting_p; str_arg_l = p - starting_p; ! 930: /* well, not exactly so for Linux, which does something inbetween, ! 931: * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y" */ ! 932: #else ! 933: /* discard the unrecognized conversion, just keep * ! 934: * the unrecognized conversion character */ ! 935: str_arg = p; str_arg_l = 0; ! 936: #endif ! 937: if (*p) str_arg_l++; /* include invalid conversion specifier unchanged ! 938: if not at end-of-string */ ! 939: break; ! 940: } ! 941: if (*p) p++; /* step over the just processed conversion specifier */ ! 942: /* insert padding to the left as requested by min_field_width; ! 943: this does not include the zero padding in case of numerical conversions*/ ! 944: if (!justify_left) { /* left padding with blank or zero */ ! 945: int n = min_field_width - (str_arg_l+number_of_zeros_to_pad); ! 946: if (n > 0) { ! 947: if (str_l < str_m) { ! 948: size_t avail = str_m-str_l; ! 949: fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n)); ! 950: } ! 951: str_l += n; ! 952: } ! 953: } ! 954: /* zero padding as requested by the precision or by the minimal field width ! 955: * for numeric conversions required? */ ! 956: if (number_of_zeros_to_pad <= 0) { ! 957: /* will not copy first part of numeric right now, * ! 958: * force it to be copied later in its entirety */ ! 959: zero_padding_insertion_ind = 0; ! 960: } else { ! 961: /* insert first part of numerics (sign or '0x') before zero padding */ ! 962: int n = zero_padding_insertion_ind; ! 963: if (n > 0) { ! 964: if (str_l < str_m) { ! 965: size_t avail = str_m-str_l; ! 966: fast_memcpy(str+str_l, str_arg, (n>avail?avail:n)); ! 967: } ! 968: str_l += n; ! 969: } ! 970: /* insert zero padding as requested by the precision or min field width */ ! 971: n = number_of_zeros_to_pad; ! 972: if (n > 0) { ! 973: if (str_l < str_m) { ! 974: size_t avail = str_m-str_l; ! 975: fast_memset(str+str_l, '0', (n>avail?avail:n)); ! 976: } ! 977: str_l += n; ! 978: } ! 979: } ! 980: /* insert formatted string ! 981: * (or as-is conversion specifier for unknown conversions) */ ! 982: { int n = str_arg_l - zero_padding_insertion_ind; ! 983: if (n > 0) { ! 984: if (str_l < str_m) { ! 985: size_t avail = str_m-str_l; ! 986: fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind, ! 987: (n>avail?avail:n)); ! 988: } ! 989: str_l += n; ! 990: } ! 991: } ! 992: /* insert right padding */ ! 993: if (justify_left) { /* right blank padding to the field width */ ! 994: int n = min_field_width - (str_arg_l+number_of_zeros_to_pad); ! 995: if (n > 0) { ! 996: if (str_l < str_m) { ! 997: size_t avail = str_m-str_l; ! 998: fast_memset(str+str_l, ' ', (n>avail?avail:n)); ! 999: } ! 1000: str_l += n; ! 1001: } ! 1002: } ! 1003: } ! 1004: } ! 1005: #if defined(NEED_SNPRINTF_ONLY) ! 1006: va_end(ap); ! 1007: #endif ! 1008: if (str_m > 0) { /* make sure the string is null-terminated ! 1009: even at the expense of overwriting the last character ! 1010: (shouldn't happen, but just in case) */ ! 1011: str[str_l <= str_m-1 ? str_l : str_m-1] = '\0'; ! 1012: } ! 1013: /* Return the number of characters formatted (excluding trailing null ! 1014: * character), that is, the number of characters that would have been ! 1015: * written to the buffer if it were large enough. ! 1016: * ! 1017: * The value of str_l should be returned, but str_l is of unsigned type ! 1018: * size_t, and snprintf is int, possibly leading to an undetected ! 1019: * integer overflow, resulting in a negative return value, which is illegal. ! 1020: * Both XSH5 and ISO C99 (at least the draft) are silent on this issue. ! 1021: * Should errno be set to EOVERFLOW and EOF returned in this case??? ! 1022: */ ! 1023: return (int) str_l; ! 1024: } ! 1025: #endif
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