main loop

.gitignore

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+main
+target
+
+main.dSYM/
+target.dSYM/

.gitmodules

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+[submodule "linenoise"]
+	path = linenoise
+	url = https://github.com/antirez/linenoise.git

compile.sh

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+# Compile the debugger
+gcc -g -o main -I./include -I./linenoise main.c src/debugger.c linenoise/linenoise.c
+
+# Compile the test program
+gcc -g -o target target.c

compile_flags.txt

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+-std=gnu11
+-I./include
+-I./linenoise
+ca

include/debugger.h

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+#include <sys/_types/_pid_t.h>
+
+typedef struct debugger_s debugger_t;
+
+debugger_t *debugger_create(char *program_name, pid_t pid);
+void debugger_destroy(debugger_t *debugger);
+
+void debugger_run(debugger_t *debugger);

main.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+
+#include "debugger.h"
+
+int main(int argc, char* argv[]) {
+	if (argc < 2) {
+		printf("Usage: %s <filename>\n", argv[0]);
+		return 1;
+	}
+
+	char * prog = argv[1];
+
+	int pid = fork();
+	if (pid == 0) {
+		// child
+		ptrace(PT_TRACE_ME, 0, NULL, 0);
+		execl(prog, prog, NULL);
+	} else {
+		// parent
+		printf("Started debugging %s with pid %d\n", prog, pid);
+		debugger_t *dbg = debugger_create(prog, pid);
+		debugger_run(dbg);
+	}
+
+	exit(0);
+}

src/debugger.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/_types/_pid_t.h>
+
+#include "linenoise.h"
+
+typedef struct debugger_s {
+	char * program_name;
+	pid_t pid;
+} debugger_t;
+
+debugger_t *debugger_create(char *program_name, pid_t pid) {
+	debugger_t *debugger = malloc(sizeof(debugger_t));
+	debugger->program_name = program_name;
+	debugger->pid = pid;
+	return debugger;
+}
+
+
+static void debugger_handle_command(debugger_t *debugger, char *line) {
+	printf("Command: %s\n", line);
+}
+
+void debugger_run(debugger_t *debugger) {
+	int wait_status;
+	int options = 0;
+	waitpid(debugger->pid, &wait_status, options);
+
+	char *line = NULL;
+		while ((line = linenoise("dbg> ")) != NULL) {
+			debugger_handle_command(debugger, line);
+			linenoiseHistoryAdd(line);
+			linenoiseFree(line);
+	};
+}
+
+void debugger_destroy(debugger_t *debugger) {
+	free(debugger);
+}

target.c

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+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+	printf("Hello, world!\n");
+	return 0;
+}