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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /*- |
| 2 | * Copyright (c) 1996 Peter Wemm <peter@freebsd.org> |
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| 3 | * |
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| 4 | * Redistribution and use in source and binary forms, with or without |
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| 5 | * modification, are permitted provided that the following conditions |
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| 6 | * are met: |
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| 7 | * 1. Redistributions of source code must retain the above copyright |
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| 8 | * notice, this list of conditions and the following disclaimer. |
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| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer in the |
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| 11 | * documentation and/or other materials provided with the distribution. |
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| 12 | * |
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| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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| 14 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 15 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 16 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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| 17 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 18 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 19 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 20 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 21 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 22 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 23 | * SUCH DAMAGE. |
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| 24 | */ |
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| 25 | |||
| 26 | #if defined(LIBC_RCS) && !defined(lint) |
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| 27 | static char rcsid[] = "$\Id: vasprintf.c,v 1.3 1996/07/28 16:16:11 peter Exp $"; |
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| 28 | #endif /* LIBC_RCS and not lint */ |
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| 29 | |||
| 30 | #include <stdio.h> |
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| 31 | #include <stdlib.h> |
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| 32 | |||
| 33 | #if __STDC__ |
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| 34 | #include <stdarg.h> |
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| 35 | #else |
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| 36 | #include <varargs.h> |
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| 37 | #endif |
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| 38 | |||
| 39 | #define CHUNK_SPARE 128 /* how much spare to allocate to avoid realloc calls */ |
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| 40 | |||
| 41 | struct bufcookie { |
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| 42 | char *base; /* start of buffer */ |
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| 43 | size_t size; |
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| 44 | size_t left; |
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| 45 | }; |
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| 46 | |||
| 47 | static int writehook __P((void *cookie, const char *, int)); |
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| 48 | |||
| 49 | static int |
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| 50 | writehook(cookie, buf, len) |
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| 51 | void *cookie; |
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| 52 | const char *buf; |
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| 53 | int len; |
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| 54 | { |
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| 55 | struct bufcookie *h = (struct bufcookie *)cookie; |
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| 56 | char *newbuf; |
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| 57 | |||
| 58 | if (len == 0) |
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| 59 | return 0; |
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| 60 | |||
| 61 | if (len > h->left) { |
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| 62 | /* grow malloc region */ |
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| 63 | /* |
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| 64 | * XXX this is linearly expanded, which is slow for obscenely |
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| 65 | * large strings. |
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| 66 | */ |
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| 67 | h->left = h->left + len + CHUNK_SPARE; |
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| 68 | h->size = h->size + len + CHUNK_SPARE; |
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| 69 | newbuf = realloc(h->base, h->size); |
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| 70 | if (newbuf == NULL) { |
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| 71 | free(h->base); |
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| 72 | h->base = NULL; |
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| 73 | return (-1); |
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| 74 | } else |
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| 75 | h->base = newbuf; |
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| 76 | } |
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| 77 | /* "write" it */ |
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| 78 | (void)memcpy(h->base + h->size - h->left, buf, (size_t)len); |
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| 79 | h->left -= len; |
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| 80 | return (len); |
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| 81 | } |
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| 82 | |||
| 83 | |||
| 84 | int |
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| 85 | vasprintf(str, fmt, ap) |
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| 86 | char **str; |
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| 87 | const char *fmt; |
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| 88 | va_list ap; |
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| 89 | { |
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| 90 | int ret; |
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| 91 | FILE *f; |
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| 92 | struct bufcookie h; |
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| 93 | |||
| 94 | h.base = malloc(CHUNK_SPARE); |
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| 95 | if (h.base == NULL) |
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| 96 | return (-1); |
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| 97 | h.size = CHUNK_SPARE; |
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| 98 | h.left = CHUNK_SPARE; |
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| 99 | |||
| 100 | f = funopen(&h, NULL, writehook, NULL, NULL); |
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| 101 | if (f == NULL) { |
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| 102 | free(h.base); |
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| 103 | return (-1); |
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| 104 | } |
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| 105 | ret = vfprintf(f, fmt, ap); |
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| 106 | fclose(f); |
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| 107 | if (ret < 0) { |
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| 108 | free(h.base); |
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| 109 | return (-1); |
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| 110 | } |
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| 111 | if (h.base == NULL) /* failed to realloc in writehook */ |
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| 112 | return (-1); |
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| 113 | |||
| 114 | h.base[h.size - h.left] = '\0'; |
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| 115 | *str = realloc(h.base, (size_t)(h.size - h.left + 1)); |
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| 116 | if (*str == NULL) /* failed to realloc it to actual size */ |
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| 117 | *str = h.base; /* return oversize buffer */ |
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| 118 | return (ret); |
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| 119 | } |