From a2a94981fef0b8a5775ebf476c4102a275716a53 Mon Sep 17 00:00:00 2001
From: Mattia Cabrini <dev@mattiacabrini.com>
Date: Sun, 14 Apr 2024 21:40:44 +0200
Subject: [PATCH] Better config

---
 Makefile |   4 +--
 main.c   | 103 +++++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 95 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index 3529b6a..3eb5bee 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ clear:
 all: build
 
 run: build
-	./main main.c "cat main.c"
+	./main --path main.c --comm "cat main.c"
 
 run-debug: debug
-	gdb ./main main.c "cat main.c"
+	gdb ./main --path main.c --comm "cat main.c"
diff --git a/main.c b/main.c
index 624b5ad..fb014c3 100644
--- a/main.c
+++ b/main.c
@@ -26,6 +26,7 @@ SOFTWARE.
 #include <stdlib.h>
 #include <unistd.h>
 #include <limits.h>
+#include <string.h>
 
 #include <sys/stat.h>
 #include <sys/inotify.h>
@@ -35,6 +36,9 @@ typedef int bool;
 const int true = 1;
 const int false = 0;
 
+char *file_path = NULL; // from argv
+char *comm = NULL; // to be freed
+
 const char* init_watch(int *fd, int *wd, char *path) {
 	*fd = inotify_init();
 	
@@ -103,22 +107,101 @@ bool read_inotify_e(int fd, struct inotify_event *e) {
 	return true;
 }
 
+size_t strsize(char *str) {
+	return (strlen(str) + 1) * sizeof(char);
+}
+
+char* load_config(int argc, char **argv) {
+	int i, what, comm_flag = -1, tot_len;
+	
+	for (i = 1; i < argc && comm_flag == -1; ++i) {
+		char *arg = argv[i];
+
+		if (strncmp(arg, "--path", strsize("--path")) == 0 || strncmp(arg, "-p", strsize("-p")) == 0) {
+			if (i == argc - 1) {
+				return "could not read path: no more args";
+			}
+			
+			file_path = argv[++i];
+
+			continue;
+		}
+
+		if (strncmp(arg, "--comm", strsize("--comm")) == 0 || strncmp(arg, "-c", strsize("-c")) == 0) {
+			if (i == argc - 1) {
+				return "could not read coomand: no more args";
+			}
+			
+			comm_flag = i;
+			continue;
+		}
+	}
+	
+	if (comm_flag == -1) {
+		return "no command provided";
+	}
+
+	for (i = comm_flag + 1; i < argc; ++i) {
+		tot_len += strlen(argv[i]) + 1;
+	}
+	tot_len += 1;
+	
+	comm = (char *) calloc(sizeof(char) * tot_len, '\0');
+	for (i = comm_flag + 1; i < argc; ++i) {
+		sprintf(comm, "%s%s%s", comm, comm[0] == 0 ? "" : " ", argv[i]);
+	}
+
+	return NULL;
+}
+
+void fatal(int status) {
+	if(comm != NULL) {
+		free(comm);
+	}
+
+	exit(status);
+}
+
+void check_config_fatal() {
+	bool ok = true;
+
+	if (file_path == NULL) {
+		fprintf(stderr, "no path provided");
+		ok = false;
+	}
+	
+	if (comm == NULL) {
+		fprintf(stderr, "no command provided");
+		ok = false;
+	}
+
+	if (!ok) {
+		fatal(1);
+	}
+}
+
 // argv[1]: file path
 // argv[2]: command
 int main(int argc, char **argv) {
 	const char *err;
-	char *file_path;
 	
 	int fd;
 	int wd;
 	ino_t st_ino;
 
-	if (argc < 3) {
-		printf("Usage: run_at_change file_path comm...\n");
-		exit(1);
+	// if (argc < 3) {
+	//	printf("Usage: run_at_change file_path comm...\n");
+	//	fatal(1);
+	// }
+	
+	err = load_config(argc, argv);
+	
+	if (err != NULL) {
+		fprintf(stderr, "%s\n", err);
+		fatal(1);
 	}
 	
-	file_path = argv[1];
+	check_config_fatal();
 
 	printf("monitoring %s\n", file_path);
 
@@ -126,12 +209,12 @@ int main(int argc, char **argv) {
 
 	if (err != NULL) {
 		fprintf(stderr, "%s\n", err);
-		exit(1);
+		fatal(1);
 	}
 
 	if (!reg_file_exists(file_path, &st_ino)) {
 		fprintf(stderr, "the file %s does not exist\n", file_path);
-		exit(1);
+		fatal(1);
 	}
 	
 	size_t sz_buf = sizeof(struct inotify_event) + NAME_MAX + 1;
@@ -167,15 +250,15 @@ int main(int argc, char **argv) {
 				
 				if (err != NULL) {
 					fprintf(stderr, "%s\n", err);
-					exit(1);
+					fatal(1);
 				}
 			}
 			
-			system(argv[2]);
+			system(comm);
 		}
 	}
 	
 	close_watch(&fd, &wd);
 
-	return fd == 0 ? 1 : 0;
+	fatal(0);
 }
-- 
2.43.0