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);
+}

src/util.c

@@ -0,0 +1,51 @@
+#include <odweta/util.h>
+#include <odweta/vector.h>
+
+char*
+intToString(int x) {
+    vector_t* string = vectorInit(CHAR);
+
+    if (x > 0 && x < 10) {
+        vectorPush(string, &(char){x+48});
+        char* retval = (char*)vectorToString(string);
+        vectorCleanup(string);
+        return retval;
+    } else {
+        while (x > 0) {
+            int lastDigit = x % 10;
+            x /= 10;
+            vectorInsertAt(string, 0, &(char){lastDigit+48});
+        }
+        vectorPop(string);
+        char* retval = (char*)vectorToString(string);
+        vectorCleanup(string);
+        return retval;
+    }
+}
+
+long
+pow(int x, int n) {
+    long retval = 1;
+
+    for (int i = 0; i < n; i++) {
+        retval *= x;
+    }
+
+    return retval;
+}
+
+int
+maxLowerPowerOf10(int x) {
+    int i = 0;
+    long prev = pow(10, i++);
+
+    while (1) {
+        long now = pow(10, i);
+        if (now >= x) {
+            return (int)prev;
+        }
+        prev = now;
+        i++;
+    }
+
+}

src/vector.c

@@ -324,7 +324,9 @@ vectorGetAt(vector_t* v, int index) {
 
 void
 vectorSetAt(vector_t* v, int index, void* element) {
-    if (index >= v->size) {
+    if (v->size == 0) {
+        vectorPush(v, element);
+    } else if (index >= v->size) {
         fprintf(stderr, "index out of range\n");
         exit(EXIT_FAILURE);
     }
@@ -350,7 +352,9 @@ vectorSetAt(vector_t* v, int index, void* element) {
 
 void
 vectorInsertAt(vector_t* v, int index, void* element) {
-    if (index >= v->size) {
+    if (v->size == 0) {
+        vectorPush(v, element);
+    } else if (index >= v->size) {
         fprintf(stderr, "index out of range\n");
         exit(EXIT_FAILURE);
     }