My first quine.

quine.m

#include <stdio.h>
#include <string.h>

int main(void)
{
    char* code = "#include <stdio.h>\n#include <string.h>\n\nint main(void)\n{\n    char* code = \"%s\";\n\n    int len = strlen(code);\n    int tokenStarted = 0;\n    for (int i = 0; i < len; i++)\n    {\n        char c = code[i];\n\n        if (tokenStarted == 1)\n        {\n            if (c == 's')\n            {\n                for (int j = 0; j < len; j++)\n                {\n                    char d = code[j];\n\n                    if (d == '\\n')\n                    {\n                        putchar('\\\\');\n                        putchar('n');\n                    }\n                    else if (d == '\\\"')\n                    {\n                        putchar('\\\\');\n                        putchar('\\\"');\n                    }\n                    else if (d == '\\\\')\n                    {\n                        putchar('\\\\');\n                        putchar('\\\\');\n                    }\n                    else\n                    {\n                        putchar(d);\n                    }\n                }\n            }\n            else\n            {\n                putchar('%');\n                putchar(c);\n            }\n            tokenStarted = 0;\n        }\n        else if (c == '%')\n        {\n            tokenStarted = 1;\n        }\n        else\n        {\n            putchar(c);\n        }\n    }\n}\n";

    int len = strlen(code);
    int tokenStarted = 0;
    for (int i = 0; i < len; i++)
    {
        char c = code[i];

        if (tokenStarted == 1)
        {
            if (c == 's')
            {
                for (int j = 0; j < len; j++)
                {
                    char d = code[j];

                    if (d == '\n')
                    {
                        putchar('\\');
                        putchar('n');
                    }
                    else if (d == '\"')
                    {
                        putchar('\\');
                        putchar('\"');
                    }
                    else if (d == '\\')
                    {
                        putchar('\\');
                        putchar('\\');
                    }
                    else
                    {
                        putchar(d);
                    }
                }
            }
            else
            {
                putchar('%');
                putchar(c);
            }
            tokenStarted = 0;
        }
        else if (c == '%')
        {
            tokenStarted = 1;
        }
        else
        {
            putchar(c);
        }
    }
}