1 /* getdelim.c --- Implementation of replacement getdelim function. 2 Copyright (C) 1994, 1996-1998, 2001, 2003, 2005-2022 Free Software 3 Foundation, Inc. 4 5 This file is free software: you can redistribute it and/or modify 6 it under the terms of the GNU Lesser General Public License as 7 published by the Free Software Foundation; either version 2.1 of the 8 License, or (at your option) any later version. 9 10 This file is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public License 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 17 18 /* Ported from glibc by Simon Josefsson. */ 19 20 /* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc 21 optimizes away the lineptr == NULL || n == NULL || fp == NULL tests below. */ 22 #define _GL_ARG_NONNULL(params) 23 24 #include <config.h> 25 26 #include <stdio.h> 27 28 #include <limits.h> 29 #include <stdint.h> 30 #include <stdlib.h> 31 #include <errno.h> 32 33 #ifndef SSIZE_MAX 34 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2)) 35 #endif 36 37 #if USE_UNLOCKED_IO 38 # include "unlocked-io.h" 39 # define getc_maybe_unlocked(fp) getc(fp) 40 #elif !HAVE_FLOCKFILE || !HAVE_FUNLOCKFILE || !HAVE_DECL_GETC_UNLOCKED 41 # undef flockfile 42 # undef funlockfile 43 # define flockfile(x) ((void) 0) 44 # define funlockfile(x) ((void) 0) 45 # define getc_maybe_unlocked(fp) getc(fp) 46 #else 47 # define getc_maybe_unlocked(fp) getc_unlocked(fp) 48 #endif 49 50 static void 51 alloc_failed (void) 52 { 53 #if defined _WIN32 && ! defined __CYGWIN__ 54 /* Avoid errno problem without using the realloc module; see: 55 https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html */ 56 errno = ENOMEM; 57 #endif 58 } 59 60 /* Read up to (and including) a DELIMITER from FP into *LINEPTR (and 61 NUL-terminate it). *LINEPTR is a pointer returned from malloc (or 62 NULL), pointing to *N characters of space. It is realloc'ed as 63 necessary. Returns the number of characters read (not including 64 the null terminator), or -1 on error or EOF. */ 65 66 ssize_t 67 getdelim (char **lineptr, size_t *n, int delimiter, FILE *fp) 68 { 69 ssize_t result; 70 size_t cur_len = 0; 71 72 if (lineptr == NULL || n == NULL || fp == NULL) 73 { 74 errno = EINVAL; 75 return -1; 76 } 77 78 flockfile (fp); 79 80 if (*lineptr == NULL || *n == 0) 81 { 82 char *new_lineptr; 83 *n = 120; 84 new_lineptr = (char *) realloc (*lineptr, *n); 85 if (new_lineptr == NULL) 86 { 87 alloc_failed (); 88 result = -1; 89 goto unlock_return; 90 } 91 *lineptr = new_lineptr; 92 } 93 94 for (;;) 95 { 96 int i; 97 98 i = getc_maybe_unlocked (fp); 99 if (i == EOF) 100 { 101 result = -1; 102 break; 103 } 104 105 /* Make enough space for len+1 (for final NUL) bytes. */ 106 if (cur_len + 1 >= *n) 107 { 108 size_t needed_max = 109 SSIZE_MAX < SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX; 110 size_t needed = 2 * *n + 1; /* Be generous. */ 111 char *new_lineptr; 112 113 if (needed_max < needed) 114 needed = needed_max; 115 if (cur_len + 1 >= needed) 116 { 117 result = -1; 118 errno = EOVERFLOW; 119 goto unlock_return; 120 } 121 122 new_lineptr = (char *) realloc (*lineptr, needed); 123 if (new_lineptr == NULL) 124 { 125 alloc_failed (); 126 result = -1; 127 goto unlock_return; 128 } 129 130 *lineptr = new_lineptr; 131 *n = needed; 132 } 133 134 (*lineptr)[cur_len] = i; 135 cur_len++; 136 137 if (i == delimiter) 138 break; 139 } 140 (*lineptr)[cur_len] = '\0'; 141 result = cur_len ? cur_len : result; 142 143 unlock_return: 144 funlockfile (fp); /* doesn't set errno */ 145 146 return result; 147 } 148