Modify: bf: add file optional argument

docs/USERS.md

@@ -69,9 +69,9 @@ Clears the screen by scrolling (screen height) times.
 
 A math lexer & parser that can calculate simple arithmetic operations. Adding, subtracting, multiplying, dividing, and factoring are supported. (I plan to get support for trigonometric functions maybe)
 
-#### `bf`
+#### `bf <optional: file>`
 
-A brainfuck interpreter with every instruction and default tape size (30k cells).
+A brainfuck interpreter with every instruction and default tape size (30k cells). Takes an optional argument, the filename for a Brainfuck source file.
 
 #### `uptime`
 

src/initrd/hello.bf

@@ -0,0 +1 @@
+-[------->+<]>-.-[->+++++<]>++.+++++++..+++.[--->+<]>-----.---[->+++<]>.-[--->+<]>---.+++.------.--------.

src/kernel/initrd.c

@@ -102,3 +102,33 @@ void cat_initrd(uint8_t* initrd, const char* filename)
 
 	printf("File '%s' not found\n", filename);
 }
+
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer)
+{
+	uint8_t* current_block = initrd;
+
+	while (1)
+	{
+		if (current_block[0] == '\0')
+		{
+			//puts("[tar] EOF\n");
+			return -1;
+		}
+
+		const char* file_name = (const char*)current_block;
+		uint32_t file_size = tar_parse_size((const char*)(current_block+124));
+
+		if (strcmp(file_name, filename) == 0)
+		{
+			uint8_t* file_data = current_block + TAR_BLOCK_SIZE;
+			memcpy(buffer, file_data, file_size);
+			buffer[file_size] = '\0';
+			return 0;
+		}
+
+		uint32_t total_size = ((file_size + TAR_BLOCK_SIZE - 1) / TAR_BLOCK_SIZE) * TAR_BLOCK_SIZE;
+		current_block += TAR_BLOCK_SIZE + total_size;
+	}
+	printf("[tar] file '%s' not found\n", filename);
+	return -1;
+}

src/kernel/initrd.h

@@ -33,5 +33,6 @@ typedef struct
 void tar_find_file(uint8_t *tar_start, const char* filename);
 void ls_initrd(uint8_t* initrd);
 void cat_initrd(uint8_t* initrd, const char* filename);
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer);
 
 #endif

src/kernel/system.c

@@ -34,6 +34,18 @@ void *memmove(void* dest, const void* src, size_t n)
 	return dest;
 }
 
+void *memcpy(void* dest, const void* src, uint32_t n)
+{
+	uint8_t* d = (uint8_t*)dest;
+	const uint8_t* s = (const uint8_t*)src;
+
+	for (uint32_t i=0; i<n; i++)
+	{
+		d[i] = s[i];
+	}
+	return dest;
+}
+
 void panic()
 {
 	for (;;);	

src/kernel/system.h

@@ -13,6 +13,7 @@ typedef int size_t;
 
 void *memset(void *dest, char val, size_t count);
 void *memmove(void* dest, const void* src, size_t n);
+void *memcpy(void* dest, const void* src, uint32_t n);
 
 struct regs
 {

src/programs/bf.c

@@ -5,6 +5,8 @@
 
 #include "../kernel/system.h"
 #include "../libc/stdio.h"
+#include "../kernel/kmain.h"
+#include "../kernel/initrd.h"
 
 #define BUF_SIZE 256
 
@@ -48,12 +50,25 @@ void brainfuck(char* input)
 	}
 }
 
-void program_bf()
+void program_bf(int argc, char* argv[])
+{
+	if (argc == 1)
 	{
 		char input_buffer[BUF_SIZE];
 		puts("Brainfuck code? ");
 		get_input(input_buffer, BUF_SIZE);
 		brainfuck(input_buffer);
-	//brainfuck(",[.[-],]");
 		puts("\n");
+	} else if (argc == 2) {
+		// Read file content into buffer, then interpret it
+		char input_buffer[BUF_SIZE];
+		int read = tar_file_to_buffer((uint8_t*)initrd_addr, argv[1], input_buffer);
+		if (read == 0)
+		{
+			brainfuck(input_buffer);
+			puts("\n");
+		} else {
+			printf("Could not find file '%s'\n", argv[1]);
+		}
+	}
 }