/* $NetBSD: snprintf.c,v 1.2.22.1 2023/08/11 13:40:02 martin Exp $ */ /* * Copyright (c) 1995-2003 Kungliga Tekniska Högskolan * (Royal Institute of Technology, Stockholm, Sweden). * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include enum format_flags { minus_flag = 1, plus_flag = 2, space_flag = 4, alternate_flag = 8, zero_flag = 16 }; /* * Common state */ struct snprintf_state { unsigned char *str; unsigned char *s; unsigned char *theend; size_t sz; size_t max_sz; void (*append_char)(struct snprintf_state *, unsigned char); /* XXX - methods */ }; #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF) static int sn_reserve (struct snprintf_state *state, size_t n) { return state->s + n > state->theend; } static void sn_append_char (struct snprintf_state *state, unsigned char c) { if (!sn_reserve (state, 1)) *state->s++ = c; } #endif static int as_reserve (struct snprintf_state *state, size_t n) { if (state->s + n > state->theend) { int off = state->s - state->str; unsigned char *tmp; if (state->max_sz && state->sz >= state->max_sz) return 1; state->sz = max(state->sz * 2, state->sz + n); if (state->max_sz) state->sz = min(state->sz, state->max_sz); tmp = realloc (state->str, state->sz); if (tmp == NULL) return 1; state->str = tmp; state->s = state->str + off; state->theend = state->str + state->sz - 1; } return 0; } static void as_append_char (struct snprintf_state *state, unsigned char c) { if(!as_reserve (state, 1)) *state->s++ = c; } /* longest integer types */ #ifdef HAVE_LONG_LONG typedef unsigned long long u_longest; typedef long long longest; #else typedef unsigned long u_longest; typedef long longest; #endif #ifndef HAVE_UINTPTR_T typedef u_longest uintptr_t; #endif static size_t pad(struct snprintf_state *state, int width, char c) { size_t len = 0; while(width-- > 0){ (*state->append_char)(state, c); ++len; } return len; } /* return true if we should use alternatve hex form */ static int use_alternative (int flags, u_longest num, unsigned base) { return (flags & alternate_flag) && base == 16 && num != 0; } static int append_number(struct snprintf_state *state, u_longest num, unsigned base, const char *rep, int width, int prec, int flags, int minusp) { int len = 0; u_longest n = num; char nstr[64]; /* enough for <192 bit octal integers */ int nstart, nlen; char signchar; /* given precision, ignore zero flag */ if(prec != -1) flags &= ~zero_flag; else prec = 1; /* format number as string */ nstart = sizeof(nstr); nlen = 0; nstr[--nstart] = '\0'; do { assert(nstart > 0); nstr[--nstart] = rep[n % base]; ++nlen; n /= base; } while(n); /* zero value with zero precision should produce no digits */ if(prec == 0 && num == 0) { nlen--; nstart++; } /* figure out what char to use for sign */ if(minusp) signchar = '-'; else if((flags & plus_flag)) signchar = '+'; else if((flags & space_flag)) signchar = ' '; else signchar = '\0'; if((flags & alternate_flag) && base == 8) { /* if necessary, increase the precision to make first digit a zero */ /* XXX C99 claims (regarding # and %o) that "if the value and precision are both 0, a single 0 is printed", but there is no such wording for %x. This would mean that %#.o would output "0", but %#.x "". This does not make sense, and is also not what other printf implementations are doing. */ if(prec <= nlen && nstr[nstart] != '0' && nstr[nstart] != '\0') prec = nlen + 1; } /* possible formats: pad | sign | alt | zero | digits sign | alt | zero | digits | pad minus_flag sign | alt | zero | digits zero_flag */ /* if not right justifying or padding with zeros, we need to compute the length of the rest of the string, and then pad with spaces */ if(!(flags & (minus_flag | zero_flag))) { if(prec > nlen) width -= prec; else width -= nlen; if(use_alternative(flags, num, base)) width -= 2; if(signchar != '\0') width--; /* pad to width */ len += pad(state, width, ' '); } if(signchar != '\0') { (*state->append_char)(state, signchar); ++len; } if(use_alternative(flags, num, base)) { (*state->append_char)(state, '0'); (*state->append_char)(state, rep[10] + 23); /* XXX */ len += 2; } if(flags & zero_flag) { /* pad to width with zeros */ if(prec - nlen > width - len - nlen) len += pad(state, prec - nlen, '0'); else len += pad(state, width - len - nlen, '0'); } else /* pad to prec with zeros */ len += pad(state, prec - nlen, '0'); while(nstr[nstart] != '\0') { (*state->append_char)(state, nstr[nstart++]); ++len; } if(flags & minus_flag) len += pad(state, width - len, ' '); return len; } /* * return length */ static size_t append_string (struct snprintf_state *state, const unsigned char *arg, int width, int prec, int flags) { size_t len = 0; if(arg == NULL) arg = (const unsigned char*)"(null)"; if(prec != -1) width -= prec; else width -= strlen((const char *)arg); if(!(flags & minus_flag)) len += pad(state, width, ' '); if (prec != -1) { while (prec-- && *arg) { (*state->append_char) (state, *arg++); ++len; } } else { while (*arg) { (*state->append_char) (state, *arg++); ++len; } } if(flags & minus_flag) len += pad(state, width, ' '); return len; } static int append_char(struct snprintf_state *state, unsigned char arg, int width, int flags) { int len = 0; while(!(flags & minus_flag) && --width > 0) { (*state->append_char) (state, ' ') ; ++len; } (*state->append_char) (state, arg); ++len; while((flags & minus_flag) && --width > 0) { (*state->append_char) (state, ' '); ++len; } return 0; } /* * This can't be made into a function... */ #ifdef HAVE_LONG_LONG #define PARSE_INT_FORMAT(res, arg, unsig) \ if (long_long_flag) \ res = (unsig long long)va_arg(arg, unsig long long); \ else if (long_flag) \ res = (unsig long)va_arg(arg, unsig long); \ else if (size_t_flag) \ res = (unsig long)va_arg(arg, size_t); \ else if (short_flag) \ res = (unsig short)va_arg(arg, unsig int); \ else \ res = (unsig int)va_arg(arg, unsig int) #else #define PARSE_INT_FORMAT(res, arg, unsig) \ if (long_flag) \ res = (unsig long)va_arg(arg, unsig long); \ else if (size_t_flag) \ res = (unsig long)va_arg(arg, size_t); \ else if (short_flag) \ res = (unsig short)va_arg(arg, unsig int); \ else \ res = (unsig int)va_arg(arg, unsig int) #endif /* * zyxprintf - return length, as snprintf */ static size_t xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap) { const unsigned char *format = (const unsigned char *)char_format; unsigned char c; size_t len = 0; while((c = *format++)) { if (c == '%') { int flags = 0; int width = 0; int prec = -1; int size_t_flag = 0; int long_long_flag = 0; int long_flag = 0; int short_flag = 0; /* flags */ while((c = *format++)){ if(c == '-') flags |= minus_flag; else if(c == '+') flags |= plus_flag; else if(c == ' ') flags |= space_flag; else if(c == '#') flags |= alternate_flag; else if(c == '0') flags |= zero_flag; else if(c == '\'') ; /* just ignore */ else break; } if((flags & space_flag) && (flags & plus_flag)) flags ^= space_flag; if((flags & minus_flag) && (flags & zero_flag)) flags ^= zero_flag; /* width */ if (isdigit(c)) do { width = width * 10 + c - '0'; c = *format++; } while(isdigit(c)); else if(c == '*') { width = va_arg(ap, int); c = *format++; } /* precision */ if (c == '.') { prec = 0; c = *format++; if (isdigit(c)) do { prec = prec * 10 + c - '0'; c = *format++; } while(isdigit(c)); else if (c == '*') { prec = va_arg(ap, int); c = *format++; } } /* size */ if (c == 'h') { short_flag = 1; c = *format++; } else if (c == 'z') { size_t_flag = 1; c = *format++; } else if (c == 'l') { long_flag = 1; c = *format++; if (c == 'l') { long_long_flag = 1; c = *format++; } } if(c != 'd' && c != 'i') flags &= ~(plus_flag | space_flag); switch (c) { case 'c' : append_char(state, va_arg(ap, int), width, flags); ++len; break; case 's' : len += append_string(state, va_arg(ap, unsigned char*), width, prec, flags); break; case 'd' : case 'i' : { int64_t arg; uint64_t num; int minusp = 0; PARSE_INT_FORMAT(arg, ap, signed); if (arg == INT64_MIN) { minusp = 1; num = (uint64_t)INT64_MAX + 1; } else if (arg < 0) { minusp = 1; num = -arg; } else num = arg; len += append_number (state, num, 10, "0123456789", width, prec, flags, minusp); break; } case 'u' : { u_longest arg; PARSE_INT_FORMAT(arg, ap, unsigned); len += append_number (state, arg, 10, "0123456789", width, prec, flags, 0); break; } case 'o' : { u_longest arg; PARSE_INT_FORMAT(arg, ap, unsigned); len += append_number (state, arg, 010, "01234567", width, prec, flags, 0); break; } case 'x' : { u_longest arg; PARSE_INT_FORMAT(arg, ap, unsigned); len += append_number (state, arg, 0x10, "0123456789abcdef", width, prec, flags, 0); break; } case 'X' :{ u_longest arg; PARSE_INT_FORMAT(arg, ap, unsigned); len += append_number (state, arg, 0x10, "0123456789ABCDEF", width, prec, flags, 0); break; } case 'p' : { uintptr_t arg = (uintptr_t)va_arg(ap, void*); len += append_number (state, arg, 0x10, "0123456789ABCDEF", width, prec, flags, 0); break; } case 'n' : { int *arg = va_arg(ap, int*); *arg = state->s - state->str; break; } case '\0' : --format; /* FALLTHROUGH */ case '%' : (*state->append_char)(state, c); ++len; break; default : (*state->append_char)(state, '%'); (*state->append_char)(state, c); len += 2; break; } } else { (*state->append_char) (state, c); ++len; } } return len; } #if !defined(HAVE_SNPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_snprintf (char *str, size_t sz, const char *format, ...) { va_list args; int ret; va_start(args, format); ret = vsnprintf (str, sz, format, args); va_end(args); #ifdef PARANOIA { int ret2; char *tmp; tmp = malloc (sz); if (tmp == NULL) abort (); va_start(args, format); ret2 = vsprintf (tmp, format, args); va_end(args); if (ret != ret2 || strcmp(str, tmp)) abort (); free (tmp); } #endif return ret; } #endif #if !defined(HAVE_ASPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_asprintf (char **ret, const char *format, ...) { va_list args; int val; va_start(args, format); val = vasprintf (ret, format, args); va_end(args); #ifdef PARANOIA { int ret2; char *tmp; tmp = malloc (val + 1); if (tmp == NULL) abort (); va_start(args, format); ret2 = vsprintf (tmp, format, args); va_end(args); if (val != ret2 || strcmp(*ret, tmp)) abort (); free (tmp); } #endif return val; } #endif #if !defined(HAVE_ASNPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_asnprintf (char **ret, size_t max_sz, const char *format, ...) { va_list args; int val; va_start(args, format); val = vasnprintf (ret, max_sz, format, args); #ifdef PARANOIA { int ret2; char *tmp; tmp = malloc (val + 1); if (tmp == NULL) abort (); ret2 = vsprintf (tmp, format, args); if (val != ret2 || strcmp(*ret, tmp)) abort (); free (tmp); } #endif va_end(args); return val; } #endif #if !defined(HAVE_VASPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_vasprintf (char **ret, const char *format, va_list args) { return vasnprintf (ret, 0, format, args); } #endif #if !defined(HAVE_VASNPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_vasnprintf (char **ret, size_t max_sz, const char *format, va_list args) { size_t st; struct snprintf_state state; state.max_sz = max_sz; state.sz = 1; state.str = malloc(state.sz); if (state.str == NULL) { *ret = NULL; return -1; } state.s = state.str; state.theend = state.s + state.sz - 1; state.append_char = as_append_char; st = xyzprintf (&state, format, args); if (st > state.sz) { free (state.str); *ret = NULL; return -1; } else { char *tmp; *state.s = '\0'; tmp = realloc (state.str, st+1); if (tmp == NULL) { free (state.str); *ret = NULL; return -1; } *ret = tmp; return st; } } #endif #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF) ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL rk_vsnprintf (char *str, size_t sz, const char *format, va_list args) { struct snprintf_state state; int ret; unsigned char *ustr = (unsigned char *)str; state.max_sz = 0; state.sz = sz; state.str = ustr; state.s = ustr; state.theend = ustr + sz - (sz > 0); state.append_char = sn_append_char; ret = xyzprintf (&state, format, args); if (state.s != NULL && sz != 0) *state.s = '\0'; return ret; } #endif