Commit d82db3e - toy-debugger

Update readme with new debugger commands and usage examples

Author	Mitja Felicijan <mitja.felicijan@gmail.com>	2026-01-17 02:16:23 +0100
Committer	Mitja Felicijan <mitja.felicijan@gmail.com>	2026-01-17 02:16:23 +0100
Commit	`d82db3ea9a36b15aab5fae2021948ef4b96e92b0` (patch)

`-rw-r--r--`	README.md	10
`-rw-r--r--`	example.c	89

2 files changed, 57 insertions, 42 deletions

 Run the debugger with: `./tdbg <target_executable>`
+Example with arguments and environment variables:
+```sh
+./tdbg ./example arg1 arg2 arg3
+./tdbg ./example -e MYENV=qwe -- arg1 arg2 arg3
+```
 ### Interactive Commands
 | Key | Action                                                            |
 | `s` | **Step into**                                                     |
 | `o` | **Step out**                                                      |
 | `c` | **Continue** execution                                            |
+| `w` | **Watch** expression                                              |
 | `q` | **Quit** debugger                                                 |
+| `>` | **Reduces sidebar width**                                         |
+| `<` | **Increases sidebar width**                                       |
 ### Input Mode



#include <stdlib.h>
  
typedef enum {
	STATUS_IDLE,
	STATUS_RUNNING,
	STATUS_STOPPED
} Status;
  
typedef struct {
	int x;
	int y;
} Point;
  
typedef struct {
	Point top_left;
	Point bottom_right;
} Rectangle;
  
typedef struct {
	int q;
	int w;
} Bar;
  
int add_numbers(int a, int b) {
	int result = a + b;
	return result;
}
  
int fibonacci(int n) {
	if (n <= 1) return n;
	return fibonacci(n - 1) + fibonacci(n - 2);
}
  
void print_rectangle(Rectangle rect) {
	printf("> Rect: (%d, %d) to (%d, %d)\n",
			rect.top_left.x, rect.top_left.y,
			rect.bottom_right.x, rect.bottom_right.y);
}
  
int main(int argc, char **argv) {
	const char *myenv = getenv("MYENV");
  
	char *args[3];
	for (int i = 0; i < argc; i++) {
		args[i] = argv[i];
	}
  
	int a = 100;
	int b = 123;
	int c = add_numbers(a, b);
  
	Bar bar = { .q = 565, .w = 949 };
	Status status = STATUS_RUNNING;
  
	Rectangle rect = {
		.top_left = { .x = 10, .y = 20 },
		.bottom_right = { .x = 50, .y = 80 }
	};
  
	printf("> MYENV: %s\n", myenv ? myenv : "NULL");
	printf("> c: %d (via add_numbers)\n", c);
	printf("> bar.q: %d\n", bar.q);
	printf("> status: %d\n", status);
  
	print_rectangle(rect);
  
	int fib5 = fibonacci(5);
	printf("> fib(5): %d\n", fib5);
  
	int arr[] = {10, 20, 30, 40, 50};
	int *ptr = arr;
	for (int i = 0; i < 5; i++) {
		printf("> arr[%d] = %d (via ptr: %d)\n", i, arr[i], *(ptr + i));
	}
  
	for (int i = 0; i < 3; i++) {
		printf("> loop %d\n", i);
	}
  
	return 0;
}

diff --git a/example.c b/example.c
...
2	#include <stdlib.h>	2	#include <stdlib.h>
3		3
4	typedef enum {	4	typedef enum {
5	STATUS_IDLE,	5	STATUS_IDLE,
6	STATUS_RUNNING,	6	STATUS_RUNNING,
7	STATUS_STOPPED	7	STATUS_STOPPED
8	} Status;	8	} Status;
9		9
10	typedef struct {	10	typedef struct {
11	int x;	11	int x;
12	int y;	12	int y;
13	} Point;	13	} Point;
14		14
15	typedef struct {	15	typedef struct {
16	Point top_left;	16	Point top_left;
17	Point bottom_right;	17	Point bottom_right;
18	} Rectangle;	18	} Rectangle;
19		19
20	typedef struct {	20	typedef struct {
21	int q;	21	int q;
22	int w;	22	int w;
23	} Bar;	23	} Bar;
24		24
25	int add_numbers(int a, int b) {	25	int add_numbers(int a, int b) {
26	int result = a + b;	26	int result = a + b;
27	return result;	27	return result;
28	}	28	}
29		29
30	int fibonacci(int n) {	30	int fibonacci(int n) {
31	if (n <= 1) return n;	31	if (n <= 1) return n;
32	return fibonacci(n - 1) + fibonacci(n - 2);	32	return fibonacci(n - 1) + fibonacci(n - 2);
33	}	33	}
34		34
35	void print_rectangle(Rectangle rect) {	35	void print_rectangle(Rectangle rect) {
36	printf("> Rect: (%d, %d) to (%d, %d)\n",	36	printf("> Rect: (%d, %d) to (%d, %d)\n",
37	rect.top_left.x, rect.top_left.y,	37	rect.top_left.x, rect.top_left.y,
38	rect.bottom_right.x, rect.bottom_right.y);	38	rect.bottom_right.x, rect.bottom_right.y);
39	}	39	}
40		40
41	int main(int argc, char **argv) {	41	int main(int argc, char **argv) {
42	const char *myenv = getenv("MYENV");	42	const char *myenv = getenv("MYENV");
43		43
44	int a = 100;	44	char *args[3];
45	int b = 123;	45	for (int i = 0; i < argc; i++) {
46	int c = add_numbers(a, b);	46	args[i] = argv[i];
		47	}
		48
		49	int a = 100;
		50	int b = 123;
		51	int c = add_numbers(a, b);
47		52
48	Bar bar = { .q = 565, .w = 949 };	53	Bar bar = { .q = 565, .w = 949 };
49	Status status = STATUS_RUNNING;	54	Status status = STATUS_RUNNING;
50		55
51	Rectangle rect = {	56	Rectangle rect = {
52	.top_left = { .x = 10, .y = 20 },	57	.top_left = { .x = 10, .y = 20 },
53	.bottom_right = { .x = 50, .y = 80 }	58	.bottom_right = { .x = 50, .y = 80 }
54	};	59	};
55		60
56	printf("> MYENV: %s\n", myenv ? myenv : "NULL");	61	printf("> MYENV: %s\n", myenv ? myenv : "NULL");
57	printf("> c: %d (via add_numbers)\n", c);	62	printf("> c: %d (via add_numbers)\n", c);
58	printf("> bar.q: %d\n", bar.q);	63	printf("> bar.q: %d\n", bar.q);
59	printf("> status: %d\n", status);	64	printf("> status: %d\n", status);
60		65
61	print_rectangle(rect);	66	print_rectangle(rect);
62		67
63	int fib5 = fibonacci(5);	68	int fib5 = fibonacci(5);
64	printf("> fib(5): %d\n", fib5);	69	printf("> fib(5): %d\n", fib5);
65		70
66	int arr[] = {10, 20, 30, 40, 50};	71	int arr[] = {10, 20, 30, 40, 50};
67	int *ptr = arr;	72	int *ptr = arr;
68	for (int i = 0; i < 5; i++) {	73	for (int i = 0; i < 5; i++) {
69	printf("> arr[%d] = %d (via ptr: %d)\n", i, arr[i], *(ptr + i));	74	printf("> arr[%d] = %d (via ptr: %d)\n", i, arr[i], *(ptr + i));
70	}	75	}
71		76
72	for (int i = 0; i < 3; i++) {	77	for (int i = 0; i < 3; i++) {
73	printf("> loop %d\n", i);	78	printf("> loop %d\n", i);
74	}	79	}
75		80
76	return 0;	81	return 0;
77	}	82	}