made work: line numbers in files with the correct indentation level (tested on a > 1000 lines file)

src/file.c

@@ -1,5 +1,6 @@
 #include <odweta/file.h>
 #include <odweta/vector.h>
+#include <odweta/util.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -189,6 +190,7 @@ fileCopy(file_t* src, char* dst) {
 	FILE* fd = fopen(dst, "w");
     if (!fd) {
         fprintf(stderr, "could not open file for writing\n");
+        fclose(fd);
         exit(EXIT_FAILURE);
     }
 
@@ -213,6 +215,7 @@ fileDelete(file_t* f) {
         // fileCleanup(f); // don't know if this is necessary... :shrug:
         // exit(EXIT_FAILURE);
     }
+
     fileCleanup(f);
 }
 
@@ -222,3 +225,34 @@ fileMove(file_t* src, char* dst) {
 
     fileDelete(src);
 }
+
+void
+fileNumberLines(file_t* f) {
+    FILE* fd = fopen(f->path, "w");
+    if (!fd) {
+        fprintf(stderr, "could not open file for writing\n");
+        fclose(fd);
+        exit(EXIT_FAILURE);
+    }
+
+    int mlp = maxLowerPowerOf10(f->length);
+
+    for (int i = 0; i < f->length; i++) {
+        // print to the file descriptor
+        fprintf(fd, "%d %s\n", i+1, (char*)vectorToString((vector_t *)vectorGetAt(f->lines, i)));
+
+        // print to f->lines
+        vectorInsertAt((vector_t*)vectorGetAt(f->lines, i), 0, &(char){' '});
+        char* string = intToString(i+1);
+        for (int j = strlen(string)-1; j >= 0; j--) {
+            vectorInsertAt((vector_t*)vectorGetAt(f->lines, i), 0, &(char){string[j]});
+        }
+
+        // prepend the correct amount of ' '
+        for (int j = 0; j < strlen(intToString(mlp))-strlen(intToString(i+1)); j++) {
+            vectorInsertAt((vector_t*)vectorGetAt(f->lines, i), 0, &(char){' '});
+        }
+    }
+
+    fclose(fd);
+}