[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Utility routines.
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| 4 | *
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| 5 | * Copyright (C) 2005, 2006 Rob Landley <rob@landley.net>
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| 6 | * Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
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| 7 | * Copyright (C) 2001 Matt Krai
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| 8 | *
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| 9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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| 10 | */
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| 11 |
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| 12 | #include "libbb.h"
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| 13 |
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| 14 | /* This function reads an entire line from a text file, up to a newline
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| 15 | * or NUL byte, inclusive. It returns a malloc'ed char * which
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| 16 | * must be free'ed by the caller. If end is NULL '\n' isn't considered
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| 17 | * end of line. If end isn't NULL, length of the chunk is stored in it.
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| 18 | * If lineno is not NULL, *lineno is incremented for each line,
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| 19 | * and also trailing '\' is recognized as line continuation.
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| 20 | *
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| 21 | * Returns NULL if EOF/error. */
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| 22 | char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno)
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| 23 | {
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| 24 | int ch;
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| 25 | int idx = 0;
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| 26 | char *linebuf = NULL;
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| 27 | int linebufsz = 0;
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| 28 |
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| 29 | while ((ch = getc(file)) != EOF) {
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| 30 | /* grow the line buffer as necessary */
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| 31 | if (idx >= linebufsz) {
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| 32 | linebufsz += 256;
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| 33 | linebuf = xrealloc(linebuf, linebufsz);
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| 34 | }
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| 35 | linebuf[idx++] = (char) ch;
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| 36 | if (!ch)
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| 37 | break;
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| 38 | if (end && ch == '\n') {
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| 39 | if (lineno == NULL)
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| 40 | break;
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| 41 | (*lineno)++;
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| 42 | if (idx < 2 || linebuf[idx-2] != '\\')
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| 43 | break;
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| 44 | idx -= 2;
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| 45 | }
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| 46 | }
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| 47 | if (end)
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| 48 | *end = idx;
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| 49 | if (linebuf) {
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| 50 | // huh, does fgets discard prior data on error like this?
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| 51 | // I don't think so....
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| 52 | //if (ferror(file)) {
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| 53 | // free(linebuf);
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| 54 | // return NULL;
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| 55 | //}
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| 56 | linebuf = xrealloc(linebuf, idx + 1);
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| 57 | linebuf[idx] = '\0';
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| 58 | }
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| 59 | return linebuf;
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| 60 | }
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| 61 |
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| 62 | char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
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| 63 | {
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| 64 | return bb_get_chunk_with_continuation(file, end, NULL);
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| 65 | }
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| 66 |
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| 67 | /* Get line, including trailing \n if any */
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| 68 | char* FAST_FUNC xmalloc_fgets(FILE *file)
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| 69 | {
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| 70 | int i;
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| 71 |
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| 72 | return bb_get_chunk_from_file(file, &i);
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| 73 | }
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| 74 | /* Get line. Remove trailing \n */
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| 75 | char* FAST_FUNC xmalloc_fgetline(FILE *file)
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| 76 | {
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| 77 | int i;
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| 78 | char *c = bb_get_chunk_from_file(file, &i);
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| 79 |
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| 80 | if (i && c[--i] == '\n')
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| 81 | c[i] = '\0';
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| 82 |
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| 83 | return c;
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| 84 | }
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| 85 |
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| 86 | #if 0
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| 87 | /* GNUism getline() should be faster (not tested) than a loop with fgetc */
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| 88 |
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| 89 | /* Get line, including trailing \n if any */
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| 90 | char* FAST_FUNC xmalloc_fgets(FILE *file)
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| 91 | {
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| 92 | char *res_buf = NULL;
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| 93 | size_t res_sz;
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| 94 |
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| 95 | if (getline(&res_buf, &res_sz, file) == -1) {
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| 96 | free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
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| 97 | res_buf = NULL;
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| 98 | }
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| 99 | //TODO: trimming to res_sz?
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| 100 | return res_buf;
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| 101 | }
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| 102 | /* Get line. Remove trailing \n */
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| 103 | char* FAST_FUNC xmalloc_fgetline(FILE *file)
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| 104 | {
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| 105 | char *res_buf = NULL;
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| 106 | size_t res_sz;
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| 107 |
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| 108 | res_sz = getline(&res_buf, &res_sz, file);
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| 109 |
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| 110 | if ((ssize_t)res_sz != -1) {
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| 111 | if (res_buf[res_sz - 1] == '\n')
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| 112 | res_buf[--res_sz] = '\0';
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| 113 | //TODO: trimming to res_sz?
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| 114 | } else {
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| 115 | free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
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| 116 | res_buf = NULL;
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| 117 | }
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| 118 | return res_buf;
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| 119 | }
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| 120 |
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| 121 | #endif
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| 122 |
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| 123 | #if 0
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| 124 | /* Faster routines (~twice as fast). +170 bytes. Unused as of 2008-07.
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| 125 | *
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| 126 | * NB: they stop at NUL byte too.
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| 127 | * Performance is important here. Think "grep 50gigabyte_file"...
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| 128 | * Ironically, grep can't use it because of NUL issue.
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| 129 | * We sorely need C lib to provide fgets which reports size!
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| 130 | *
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| 131 | * Update:
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| 132 | * Actually, uclibc and glibc have it. man getline. It's GNUism,
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| 133 | * but very useful one (if it's as fast as this code).
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| 134 | * TODO:
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| 135 | * - currently, sed and sort use bb_get_chunk_from_file and heavily
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| 136 | * depend on its "stop on \n or \0" behavior, and STILL they fail
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| 137 | * to handle all cases with embedded NULs correctly. So:
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| 138 | * - audit sed and sort; convert them to getline FIRST.
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| 139 | * - THEN ditch bb_get_chunk_from_file, replace it with getline.
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| 140 | * - provide getline implementation for non-GNU systems.
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| 141 | */
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| 142 |
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| 143 | static char* xmalloc_fgets_internal(FILE *file, int *sizep)
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| 144 | {
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| 145 | int len;
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| 146 | int idx = 0;
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| 147 | char *linebuf = NULL;
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| 148 |
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| 149 | while (1) {
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| 150 | char *r;
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| 151 |
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| 152 | linebuf = xrealloc(linebuf, idx + 0x100);
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| 153 | r = fgets(&linebuf[idx], 0x100, file);
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| 154 | if (!r) {
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| 155 | /* need to terminate in case this is error
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| 156 | * (EOF puts NUL itself) */
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| 157 | linebuf[idx] = '\0';
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| 158 | break;
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| 159 | }
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| 160 | /* stupid. fgets knows the len, it should report it somehow */
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| 161 | len = strlen(&linebuf[idx]);
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| 162 | idx += len;
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| 163 | if (len != 0xff || linebuf[idx - 1] == '\n')
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| 164 | break;
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| 165 | }
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| 166 | *sizep = idx;
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| 167 | if (idx) {
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| 168 | /* xrealloc(linebuf, idx + 1) is up to caller */
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| 169 | return linebuf;
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| 170 | }
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| 171 | free(linebuf);
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| 172 | return NULL;
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| 173 | }
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| 174 |
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| 175 | /* Get line, remove trailing \n */
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| 176 | char* FAST_FUNC xmalloc_fgetline_fast(FILE *file)
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| 177 | {
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| 178 | int sz;
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| 179 | char *r = xmalloc_fgets_internal(file, &sz);
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| 180 | if (r && r[sz - 1] == '\n')
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| 181 | r[--sz] = '\0';
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| 182 | return r; /* not xrealloc(r, sz + 1)! */
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| 183 | }
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| 184 |
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| 185 | char* FAST_FUNC xmalloc_fgets(FILE *file)
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| 186 | {
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| 187 | int sz;
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| 188 | return xmalloc_fgets_internal(file, &sz);
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| 189 | }
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| 190 |
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| 191 | /* Get line, remove trailing \n */
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| 192 | char* FAST_FUNC xmalloc_fgetline(FILE *file)
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| 193 | {
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| 194 | int sz;
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| 195 | char *r = xmalloc_fgets_internal(file, &sz);
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| 196 | if (!r)
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| 197 | return r;
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| 198 | if (r[sz - 1] == '\n')
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| 199 | r[--sz] = '\0';
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| 200 | return xrealloc(r, sz + 1);
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| 201 | }
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| 202 | #endif
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