1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <string.h>
// okay to copy/adapt
char* _read_file_into_string(char const* filename) {
FILE* file = fopen(filename, "r");
// for loop, calling getc() until I reach the end of the file
// fseek(file, n, SEEK_CUR); // increase my position by n
// fseek(file, n, SEEK_SET); // set position to n
// fseek(file, -n, SEEK_END); // set position to end of file
// offset backwardw by -n
// e.g. -10 would be 10 characters before the end
// seek to the end of the file
fseek(file, 0, SEEK_END); // SEEK_END is relative to the end
int file_len = ftell(file); // does not include space for
// null terminator
printf("Size is %d\n", file_len + 1);
// seek to character at index 0 in the file
fseek(file, 0, SEEK_SET); // SEEK_SET is relative to the start
char* str = malloc(sizeof(*str) * (file_len + 1));
int i = 0;
for (char ch = fgetc(file); !feof(file); ch = fgetc(file)) {
str[i] = ch;
i++;
}
assert(i == file_len);
// DON'T FORGET THE NULL TERMINATOR!!
str[file_len] = '\0';
// DON'T FORGET TO CLOSE THE FILE!!
fclose(file);
printf("Value is '''\n%s\n'''\n", str);
return str;
}
int main(int argc, char* argv[]) {
char* file_contents = _read_file_into_string("example.txt");
assert(file_contents != NULL);
assert(strcmp(file_contents, "Hello World\n") == 0);
free(file_contents);
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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