pqc/src/file.c

108 lines
2.5 KiB
C

/*
* Copyright (C) 2014 FH Bielefeld
*
* This file is part of a FH Bielefeld project.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
/**
* @file file.c
* Allows operations of files, such as reading
* and writing.
* @brief file operations
*/
#include "common.h"
#include "err.h"
#include "mem.h"
#include "ntru_string.h"
#include <fcntl.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#define STD_FILE_BUF 4096
string *
read_file(char const * const filename)
{
char buf[STD_FILE_BUF],
*cstring = NULL;
int fd = 0;
size_t str_size = 0;
ssize_t n;
string *result_string;
fd = open(filename, O_RDONLY);
if (fd != -1) {
/* read and copy chunks */
while ((n = read(fd, buf, STD_FILE_BUF)) != 0) {
if (n == -1)
NTRU_ABORT("Failed while reading file descriptor %d\n", fd);
str_size += n; /* count total bytes read */
REALLOC( /* allocate correct size */
cstring, /* pointer to realloc */
str_size /* total bytes read */
+ 1); /* space for trailing NULL byte */
/* append buffer to string */
memcpy(cstring + (str_size - n), buf, (size_t)n);
}
/* add trailing NULL byte */
cstring[str_size] = '\0';
if (close(fd))
NTRU_ABORT("Failed to close file descripter %d\n", fd);
result_string = ntru_malloc(sizeof(*result_string));
result_string->ptr = cstring;
result_string->len = str_size;
return result_string;
} else {
return NULL;
}
}
void
write_file(string const *file_content, char const * const filename)
{
FILE *fp;
fp = fopen(filename, "w");
if (!fp)
NTRU_ABORT("Failed while creating file\n");
for (uint32_t i = 0; i < file_content->len; i++)
fprintf(fp, "%c", file_content->ptr[i]);
fclose(fp);
}