Making your own programming language

Code:

#include <stdio.h>

/* Filenames */
char _output[] = "a.com", _input[] = "a.txt";

/* Interpretation works also */
/* When value is 0, it will be compiled instead of interpreted. */
unsigned char interpret = 0;

/* When interpreting, this is equal to the register's al value */
unsigned char byte;

/*
The script is not implemented as a subroutine

Script prints the wanted character
Character will be printed from al register(8 byte).
Printing will happen by using suspension of DOS, 10h.
In this case, ah in register is a printed code 0Eh.
*/
char print_char[] = {
/* push bx */ 0x53,
/* push ax */ 0x50,
/* mov ah, 0Eh */ 0xB4, 0x0E,
/* xor bx, bx */ 0x33, 0xDB,
/* int 10h */ 0xCD, 0x10,
/* pop ax */ 0x58,
/* pop bx */ 0x5B
};

/*
Command increases the value of al register
*/
char increase[] = {
/* inc al */ 0xFE, 0xC0
};
/*
Command decreases the value of al register
*/
char decrease[] = {
/* dec al */ 0xFE, 0xC8
};
/*
Command initializes the program:
Register al will be set to 0.
*/
char init[] = {
/* xor al, al */ 0x32, 0xC0
};

/*
Script will leave the program by DOS suspension
*/
char quit[] = {
/* mov ah, 4Ch */ 0xB4, 0x4C,
/* int 21h*/ 0xCD, 0x21
};

/*
Takes a character for parameter and writes commands to the file which are equilevant to the parameter
*/
void write_equivalent(unsigned char command)
{
        FILE *file = 0;
        /* Open the file where the program will be written */
        if(!interpret) file = fopen(_output, "ab");

        switch(command){
                /* Following commands will be read from the file */
                case '+':
                        /* Increase the value of a characterLisätään merkin arvoa */
                        interpret?++byte:
                        /* Write the corresponding command to the file */
                        fwrite(increase, sizeof(increase), 1, file);
                        break;
                case '-':
                        /* Decrease the value of a character */
                        interpret?--byte:
                        /* Write the corresponding command to the file */
                        fwrite(decrease, sizeof(decrease), 1, file);
                        break;
                case '#':
                        /* Print characters */
                        interpret?putchar(byte):
                        /* Write the corresponding command to the file */
                        fwrite(print_char, sizeof(print_char), 1, file);
                        break;

						/* Following commands are for interval use */
                case '{':
                        /* Initialize the program */
                        interpret?byte = 0:
                        /* Write the corresponding command to the file */
                        fwrite(init, sizeof(init), 1, file);
                        break;
                case '}':
                        /* Program will be shut with an end commands */
                        if(!interpret) fwrite(quit, sizeof(quit), 1, file);
                        break;

                /* Other characters will be bypassed */
                default:
                        break;
        }

        /* Close the file if it's open */
        if(file){ fclose(file);
        /* If the file is not open and it hasn't been interpreted, show an error message */
        if(!interpret) puts("Error: File could not be opened!");}
}

int main(void)
{
        /* To read the character from the file */
        int a;

        /* Open the sourcefile */
        FILE *file;
        file = fopen(_input, "r");

        /* Check if opening the file was succesful */
        if(!file){
                puts("File could not besss opened.");
                return 1;
        }

        /* Empy the target file */
        FILE *target = fopen(_output, "w");
        fclose(target);

        /* Write the start of the program to the file */
        write_equivalent('{');

        /* We use a while-loop to read the file */
        while((a = fgetc(file)) != EOF){
                write_equivalent(a);
        }

        /* Write the end of the program to the file */
        write_equivalent('}');

        /* Close the sourcefile */
        fclose(file);
        return 0;
}

Code:

#include <stdio.h>

/* Filenames */
char _output[] = "a.com", _input[] = "a.txt";

/* Interpretation works also */
/* When value is 0, it will be compiled instead of interpreted. */
unsigned char interpret = 0;

/* When interpreting, this is equal to the register's al value */
unsigned char byte;

/*
The script is not implemented as a subroutine

Script prints the wanted character
Character will be printed from al register(8 byte).
Printing will happen by using suspension of DOS, 10h.
In this case, ah in register is a printed code 0Eh.
*/
char print_char[] = {
/* push bx */ 0x53,
/* push ax */ 0x50,
/* mov ah, 0Eh */ 0xB4, 0x0E,
/* xor bx, bx */ 0x33, 0xDB,
/* int 10h */ 0xCD, 0x10,
/* pop ax */ 0x58,
/* pop bx */ 0x5B
};

/*
Command increases the value of al register
*/
char increase[] = {
/* inc al */ 0xFE, 0xC0
};
/*
Command decreases the value of al register
*/
char decrease[] = {
/* dec al */ 0xFE, 0xC8
};
/*
Command initializes the program:
Register al will be set to 0.
*/
char init[] = {
/* xor al, al */ 0x32, 0xC0
};

/*
Script will leave the program by DOS suspension
*/
char quit[] = {
/* mov ah, 4Ch */ 0xB4, 0x4C,
/* int 21h*/ 0xCD, 0x21
};

/*
Takes a character for parameter and writes commands to the file which are equilevant to the parameter
*/
void write_equivalent(unsigned char command)
{
        FILE *file = 0;
        /* Open the file where the program will be written */
        if(!interpret) file = fopen(_output, "ab");

        switch(command){
                /* Following commands will be read from the file */
                case '+':
                        /* Increase the value of a characterLisätään merkin arvoa */
                        interpret?++byte:
                        /* Write the corresponding command to the file */
                        fwrite(increase, sizeof(increase), 1, file);
                        break;
                case '-':
                        /* Decrease the value of a character */
                        interpret?--byte:
                        /* Write the corresponding command to the file */
                        fwrite(decrease, sizeof(decrease), 1, file);
                        break;
                case '#':
                        /* Print characters */
                        interpret?putchar(byte):
                        /* Write the corresponding command to the file */
                        fwrite(print_char, sizeof(print_char), 1, file);
                        break;

						/* Following commands are for interval use */
                case '{':
                        /* Initialize the program */
                        interpret?byte = 0:
                        /* Write the corresponding command to the file */
                        fwrite(init, sizeof(init), 1, file);
                        break;
                case '}':
                        /* Program will be shut with an end commands */
                        if(!interpret) fwrite(quit, sizeof(quit), 1, file);
                        break;

                /* Other characters will be bypassed */
                default:
                        break;
        }

        /* Close the file if it's open */
        if(file){ fclose(file);
        /* If the file is not open and it hasn't been interpreted, show an error message */
        if(!interpret) puts("Error: File could not be opened!");}
}

int main(void)
{
        /* To read the character from the file */
        int a;

        /* Open the sourcefile */
        FILE *file;
        file = fopen(_input, "r");

        /* Check if opening the file was succesful */
        if(!file){
                puts("File could not besss opened.");
                return 1;
        }

        /* Empy the target file */
        FILE *target = fopen(_output, "w");
        fclose(target);

        /* Write the start of the program to the file */
        write_equivalent('{');

        /* We use a while-loop to read the file */
        while((a = fgetc(file)) != EOF){
                write_equivalent(a);
        }

        /* Write the end of the program to the file */
        write_equivalent('}');

        /* Close the sourcefile */
        fclose(file);
        return 0;
}