added writing capacilities to files and made the appropriate changes to the filedemo.c file

src/file.c

@@ -4,11 +4,15 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-int 
+int
 fileCountLines(file_t* f) {
 	char ch;
 	int lines = 0;
 	FILE* fd = fopen(f->path, "r");
+	if (!fd) {
+		fprintf(stderr, "unable to open file");
+		exit(EXIT_FAILURE);
+	}
 
 	while ((ch = fgetc(fd)) != EOF) {
 		if (ch == '\n') {
@@ -21,26 +25,44 @@ fileCountLines(file_t* f) {
 	return lines;
 }
 
-void 
-_fileLoadLines(file_t* f, FILE* fd) {
-    int lineLength;
+void
+_fileLoadLines(file_t* f) {
     char ch;
-    vector_t* line = vectorInit(CHAR);
 
+    FILE* fd = fopen(f->path, "r");
+    if (!fd) {
+        fprintf(stderr, "unable to open file %s with mode \"r\"\n", f->path);
+        fclose(fd);
+        fileCleanup(f);
+        exit(EXIT_FAILURE);
+    }
+
+    char prev;
     for (int i = 0; i < f->length; i++) {
+        vector_t* line = vectorInit(CHAR);  // Create a new vector for each line
+
         while ((ch = fgetc(fd)) != '\n' && ch != EOF) {
             vectorPush(line, &ch);
         }
 
         // Skip the newline character if it exists
         if (ch == '\n') {
-        	char* empty = "";
-        	vectorPush(line, empty);
+            char* empty = "";
+            vectorPush(line, empty);
         }
 
         vectorPush(f->lines, line);
-        line = vectorInit(CHAR);
+
+		prev = ch;
+        // Don't free the line vector here, as it's now owned by the f->lines vector
     }
+    if (prev != '\n') {
+		f->not_newline_terminated = 1; // \n is NOT at the end of a file
+	} else {
+		f->not_newline_terminated = 0; // \n IS at the end of a file
+	}
+
+    fclose(fd);
 }
 
 char* 
@@ -51,47 +73,91 @@ fileToString(file_t* f) {
 file_t* 
 fileInit(char* path) {
 	file_t* f = malloc(sizeof(file_t));
-	if (f == NULL) {
-        perror("failed to allocate memory for the file\n");
-        exit(EXIT_FAILURE);
-    }
-
-	f->lines = malloc(sizeof(vector_t));
-	if (f->lines == NULL) {
-        perror("failed to allocate memory for the file contents vector\n");
+	if (!f) {
+        fprintf(stderr, "failed to allocate memory for the file\n");
         exit(EXIT_FAILURE);
     }
 
 	f->path = path;
 
-	FILE* fd = fopen(f->path, "r");
-	if (fd == NULL) {
-		fprintf(stderr, "unable to open file %s with mode \"r\"\n", path);
-		fclose(fd);
-		fileCleanup(f);
-		exit(EXIT_FAILURE);
-	}
-
 	f->length = fileCountLines(f);
-	f->lines = vectorInit(VECTOR); // vector of vectors of chars = vector of strings
-	_fileLoadLines(f, fd);
 
-	fclose(fd);
+	f->lines = vectorInit(VECTOR); // vector of vectors of chars = vector of strings
+	_fileLoadLines(f);
 
 	return f;
 }
 
 void
 fileCleanup(file_t* f) {
+	if (f->not_newline_terminated == 1) {
+		FILE* fd = fopen(f->path, "a");
+		fprintf(fd, "\n");
+		fclose(fd);
+		f->not_newline_terminated = 0; // just for piece of mind
+	}
 	vectorCleanup(f->lines);
 	free(f);
 }
 
 void
 filePrint(file_t* f) {
-	vector_t* line = vectorInit(CHAR);
 	for (int i = 0; i < f->length; i++) {
-		line = (vector_t *)vectorGetAt(f->lines, i);
-		vectorPrintAsString(line);
+		vectorPrintAsString((vector_t *)vectorGetAt(f->lines, i));
 	}
 }
+
+void
+fileWriteln(file_t* f, char* payload) {
+    FILE* fd = fopen(f->path, "a");
+    if (!fd) {
+        fprintf(stderr, "unable to open file %s with mode \"a\"\n", f->path);
+        fclose(fd);
+        fileCleanup(f);
+        exit(EXIT_FAILURE);
+    }
+
+    fprintf(fd, "%s\n", payload);
+
+    fclose(fd);
+
+	// Update the file structure without re-initializing
+	if (f->not_newline_terminated == 0) {
+		vector_t* line = vectorInit(CHAR);
+		for (int i = 0; i < strlen(payload); i++) {
+			vectorPush(line, &payload[i]);
+		}
+		vectorPush(f->lines, line);
+		f->length++;
+		f->not_newline_terminated = 0;
+	} else if (f->not_newline_terminated == 1) {
+		for (int i = 0; i < strlen(payload); i++) {
+			vectorPush((vector_t *)vectorGetAt(f->lines, f->length-1), &payload[i]);
+		}
+		f->not_newline_terminated = 0;
+	}
+}
+
+void
+fileWrite(file_t* f, char* payload) {
+    FILE* fd = fopen(f->path, "a");
+    if (!fd) {
+        fprintf(stderr, "unable to open file %s with mode \"a\"\n", f->path);
+        fclose(fd);
+        fileCleanup(f);
+        exit(EXIT_FAILURE);
+    }
+
+    fprintf(fd, "%s", payload);
+
+    fclose(fd);
+
+    // Update the file structure without re-initializing
+	vector_t* line = vectorInit(CHAR);
+    for (int i = 0; i < strlen(payload); i++) {
+		vectorPush(line, &payload[i]);
+	}
+    vectorPush(f->lines, line);
+    f->length++;
+	f->not_newline_terminated = 1;
+}