1 /* 2 * Copyright (c) 2004 Darren Tucker. 3 * 4 * Based originally on asprintf.c from OpenBSD: 5 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include "openbsd-compat.h" 21 22 #ifndef HAVE_ASPRINTF 23 24 #include <errno.h> 25 #include <limits.h> /* for INT_MAX */ 26 #include <stdarg.h> 27 #include <stdio.h> /* for vsnprintf */ 28 #include <stdlib.h> 29 30 #define VA_COPY(dest, src) va_copy(dest, src) 31 32 #define INIT_SZ 128 33 34 int 35 vasprintf(char **str, const char *fmt, va_list ap) 36 { 37 int ret; 38 va_list ap2; 39 char *string, *newstr; 40 size_t len; 41 42 if ((string = malloc(INIT_SZ)) == NULL) 43 goto fail; 44 45 VA_COPY(ap2, ap); 46 ret = vsnprintf(string, INIT_SZ, fmt, ap2); 47 va_end(ap2); 48 if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */ 49 *str = string; 50 } else if (ret == INT_MAX || ret < 0) { /* Bad length */ 51 free(string); 52 goto fail; 53 } else { /* bigger than initial, realloc allowing for nul */ 54 len = (size_t)ret + 1; 55 if ((newstr = realloc(string, len)) == NULL) { 56 free(string); 57 goto fail; 58 } 59 VA_COPY(ap2, ap); 60 ret = vsnprintf(newstr, len, fmt, ap2); 61 va_end(ap2); 62 if (ret < 0 || (size_t)ret >= len) { /* failed with realloc'ed string */ 63 free(newstr); 64 goto fail; 65 } 66 *str = newstr; 67 } 68 return (ret); 69 70 fail: 71 *str = NULL; 72 errno = ENOMEM; 73 return (-1); 74 } 75 76 int asprintf(char **str, const char *fmt, ...) 77 { 78 va_list ap; 79 int ret; 80 81 *str = NULL; 82 va_start(ap, fmt); 83 ret = vasprintf(str, fmt, ap); 84 va_end(ap); 85 86 return ret; 87 } 88 #endif 89