How to write the string representation of the contents of a file? - c++

Question

In my file let's assume it has the following content:
my_file.txt
/* My file "\n". */
Hello World
If I wanted generate a file and pass this same content as a string in C code, the new file would look like this:
my_generated_c_file.c
const char my_file_as_string[] = "/* My file \"\\n\". */\nHello World\n\n";
In an unfortunate attempt, I tried to simply add the chars one by one:
#include <stdio.h>
int main ()
{
FILE *fp_in = fopen("my_file.txt", "r");
FILE *fp_out = fopen("my_generated_c_file.c", "w");
fseek(fp_in, 0L, SEEK_END);
long size = ftell(fp_in);
fseek(fp_in, 0L, SEEK_SET);
fprintf(fp_out, "const char my_file_as_string[] = \"");
while (size--) {
fprintf(fp_out, "%c", getc(fp_in));
}
fprintf(fp_out, \";\n\n");
fclose(fp_in);
fclose(fp_out);
return 0;
}
But that doesn't work because a '\n' for example is read as a line break and not "\\n".
How to solve this?

Answer 1

You could simply print a '\\' wherever a '\' was present in the original file:
while (size--) {
char next_c = getc(fp_in);
if(next_c == '\\') {
fputs("\\\\", fp_out);
}
else {
fputc(next_c, fp_out);
}
}
You'll probably also want to perform other such transformations as well, such as replacing line breaks with \n.