feat(utilities): added cut_path and combine_path to modify paths for storage and later usage in the file system

include/utilities.h

@@ -89,4 +89,39 @@ void visualize_diff(File* old_version, File* new_version, ActionList* actions) {
     free(inserted_lines);
 }
 
+// In this function we assume that base is a prefix of path
+// Thus we just need the length of the base to jump ahead in the path
+void cut_path(char* base, char* path) {
+    size_t base_len = strlen(base);
+    if (strlen(path) < base_len) perror("ERROR: the provided path is smaller than the base path!");
+    int add = strlen(path) != base_len ? 1 : 0;
+
+    printf("base: %li\n", base_len);
+    strcpy(path, path+base_len+add);
+
+    if (add) {
+        char tmp[PATH_MAX];
+        snprintf(tmp, sizeof(tmp), "%s/", path);
+        strcpy(path, tmp);
+    }
+}
+
+// In this function we assume that the end of the base and the beginning of the
+// path are the same so we can concat them together at that part
+// The path gets mutated in place
+void combine_path(char* base, char* path) {
+    size_t base_len = 0;
+
+    for (size_t idx = strlen(base); idx > 0; idx--) {
+        if (base[idx] == '/') {
+            base_len = idx;
+            break;
+        }
+    }
+
+    char tmp[PATH_MAX];
+    snprintf(tmp, sizeof(tmp), "%*s/%s", base_len, base, path);
+    strcpy(path, tmp);
+}
+
 #endif // UTILITIES_H

src/tree.c

@@ -73,6 +73,11 @@ static char* join_path(const char* a, const char* b) {
     return s;
 }
 
+// A function that returns the system path of the where the closest merk
+// directory to the current working directory is located up in direction to
+// the filesystem root
+// Mutates relative in place to get the correct amount of ../ in relation to
+// the directory which the software was called in
 char* find_root(char* relative) {
     char* current_dir = calloc(PATH_MAX, sizeof(char));
     if (!current_dir) {