diff options
Diffstat (limited to 'lib/getdelim.c')
-rw-r--r-- | lib/getdelim.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/lib/getdelim.c b/lib/getdelim.c new file mode 100644 index 0000000..fb39b46 --- /dev/null +++ b/lib/getdelim.c @@ -0,0 +1,147 @@ +/* getdelim.c --- Implementation of replacement getdelim function. + Copyright (C) 1994, 1996-1998, 2001, 2003, 2005-2020 Free Software + Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 3, or (at + your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <https://www.gnu.org/licenses/>. */ + +/* Ported from glibc by Simon Josefsson. */ + +/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc + optimizes away the lineptr == NULL || n == NULL || fp == NULL tests below. */ +#define _GL_ARG_NONNULL(params) + +#include <config.h> + +#include <stdio.h> + +#include <limits.h> +#include <stdint.h> +#include <stdlib.h> +#include <errno.h> + +#ifndef SSIZE_MAX +# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2)) +#endif + +#if USE_UNLOCKED_IO +# include "unlocked-io.h" +# define getc_maybe_unlocked(fp) getc(fp) +#elif !HAVE_FLOCKFILE || !HAVE_FUNLOCKFILE || !HAVE_DECL_GETC_UNLOCKED +# undef flockfile +# undef funlockfile +# define flockfile(x) ((void) 0) +# define funlockfile(x) ((void) 0) +# define getc_maybe_unlocked(fp) getc(fp) +#else +# define getc_maybe_unlocked(fp) getc_unlocked(fp) +#endif + +static void +alloc_failed (void) +{ +#if defined _WIN32 && ! defined __CYGWIN__ + /* Avoid errno problem without using the realloc module; see: + https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html */ + errno = ENOMEM; +#endif +} + +/* Read up to (and including) a DELIMITER from FP into *LINEPTR (and + NUL-terminate it). *LINEPTR is a pointer returned from malloc (or + NULL), pointing to *N characters of space. It is realloc'ed as + necessary. Returns the number of characters read (not including + the null terminator), or -1 on error or EOF. */ + +ssize_t +getdelim (char **lineptr, size_t *n, int delimiter, FILE *fp) +{ + ssize_t result; + size_t cur_len = 0; + + if (lineptr == NULL || n == NULL || fp == NULL) + { + errno = EINVAL; + return -1; + } + + flockfile (fp); + + if (*lineptr == NULL || *n == 0) + { + char *new_lineptr; + *n = 120; + new_lineptr = (char *) realloc (*lineptr, *n); + if (new_lineptr == NULL) + { + alloc_failed (); + result = -1; + goto unlock_return; + } + *lineptr = new_lineptr; + } + + for (;;) + { + int i; + + i = getc_maybe_unlocked (fp); + if (i == EOF) + { + result = -1; + break; + } + + /* Make enough space for len+1 (for final NUL) bytes. */ + if (cur_len + 1 >= *n) + { + size_t needed_max = + SSIZE_MAX < SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX; + size_t needed = 2 * *n + 1; /* Be generous. */ + char *new_lineptr; + + if (needed_max < needed) + needed = needed_max; + if (cur_len + 1 >= needed) + { + result = -1; + errno = EOVERFLOW; + goto unlock_return; + } + + new_lineptr = (char *) realloc (*lineptr, needed); + if (new_lineptr == NULL) + { + alloc_failed (); + result = -1; + goto unlock_return; + } + + *lineptr = new_lineptr; + *n = needed; + } + + (*lineptr)[cur_len] = i; + cur_len++; + + if (i == delimiter) + break; + } + (*lineptr)[cur_len] = '\0'; + result = cur_len ? cur_len : result; + + unlock_return: + funlockfile (fp); /* doesn't set errno */ + + return result; +} |