mirror of
https://https.git.savannah.gnu.org/git/gnulib.git
synced 2026-10-03 15:50:18 +00:00
Simon Josefsson
7a8df33d7b
* read-file.c (fread_file): Start with buffer allocation of 0 bytes rather than 1 byte; this simplifies the code. Don't invoke feof; it's not needed. Refactor to avoid duplicate code to free buffer and save/restore errno. (internal_read_file): Remove unused local.
139 lines
3.5 KiB
C
139 lines
3.5 KiB
C
/* read-file.c -- read file contents into a string
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Copyright (C) 2006 Free Software Foundation, Inc.
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Written by Simon Josefsson and Bruno Haible.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "read-file.h"
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/* Get realloc, free. */
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#include <stdlib.h>
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/* Get errno. */
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#include <errno.h>
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/* Read a STREAM and return a newly allocated string with the content,
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and set *LENGTH to the length of the string. The string is
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zero-terminated, but the terminating zero byte is not counted in
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*LENGTH. On errors, *LENGTH is undefined, errno preserves the
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values set by system functions (if any), and NULL is returned. */
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char *
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fread_file (FILE * stream, size_t * length)
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{
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char *buf = NULL;
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size_t alloc = 0;
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size_t size = 0;
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int save_errno;
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for (;;)
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{
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size_t count;
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size_t requested;
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if (size + BUFSIZ + 1 > alloc)
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{
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char *new_buf;
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alloc += alloc / 2;
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if (alloc < size + BUFSIZ + 1)
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alloc = size + BUFSIZ + 1;
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new_buf = realloc (buf, alloc);
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if (!new_buf)
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{
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save_errno = errno;
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break;
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}
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buf = new_buf;
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}
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requested = alloc - size - 1;
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count = fread (buf + size, 1, requested, stream);
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size += count;
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if (count != requested)
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{
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save_errno = errno;
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if (ferror (stream))
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break;
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buf[size] = '\0';
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*length = size;
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return buf;
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}
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}
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free (buf);
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errno = save_errno;
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return NULL;
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}
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static char *
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internal_read_file (const char *filename, size_t * length, const char *mode)
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{
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FILE *stream = fopen (filename, mode);
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char *out;
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int save_errno;
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if (!stream)
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return NULL;
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out = fread_file (stream, length);
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save_errno = errno;
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if (fclose (stream) != 0)
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{
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if (out)
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{
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save_errno = errno;
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free (out);
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}
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errno = save_errno;
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return NULL;
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}
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return out;
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}
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/* Open and read the contents of FILENAME, and return a newly
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allocated string with the content, and set *LENGTH to the length of
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the string. The string is zero-terminated, but the terminating
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zero byte is not counted in *LENGTH. On errors, *LENGTH is
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undefined, errno preserves the values set by system functions (if
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any), and NULL is returned. */
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char *
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read_file (const char *filename, size_t * length)
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{
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return internal_read_file (filename, length, "r");
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}
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/* Open (on non-POSIX systems, in binary mode) and read the contents
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of FILENAME, and return a newly allocated string with the content,
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and set LENGTH to the length of the string. The string is
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zero-terminated, but the terminating zero byte is not counted in
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the LENGTH variable. On errors, *LENGTH is undefined, errno
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preserves the values set by system functions (if any), and NULL is
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returned. */
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char *
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read_binary_file (const char *filename, size_t * length)
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{
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return internal_read_file (filename, length, "rb");
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}
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