helping comments on shell

src/shell/tags.c

@@ -6,8 +6,13 @@ bool shell_run_tags(struct shell *restrict shell, struct error *restrict error)
     struct tags_query_input query_input;
     struct tags_query_buf query_buf;
 
+    /* Initializes tags query's input tags with initial capacity for 2. */
     tags_query_input_init(&query_input, 2, error);
 
+    /*
+     * Reads all arguments from the command line, and adds tags corresponding
+     * to each argument to the query input.
+     */
     while (error->code == error_none) {
         shell_read_quoted_arg(shell, error);
         if (error->code == error_none) {
@@ -25,6 +30,7 @@ bool shell_run_tags(struct shell *restrict shell, struct error *restrict error)
         error_set_code(error, error_none);
     }
 
+    /* Checks the error code and executes the query if everything is ok. */
     switch (error->code) {
         case error_none:
             tags_query_init(&query_buf);

src/shell/topn.c

@@ -13,26 +13,31 @@ bool shell_run_topn(struct shell *restrict shell, struct error *restrict error)
 
     start = shell->buf->ptr + (sizeof("top") - 1);
 
+    /* Converts the "N" string into the maximum unsigned integer. */
     converted = strtoumax(start, &end, 10);
 
+    /* If the end pointer is not at the end, an error happened. */
     if (*end != 0) {
         error_set_code(error, error_topn_count);
         error->data.topn_count.string = start;
         error->data.topn_count.free_string = false;
     }
 
+    /*
+     * Reads the quoted argument, expects the end of the line, and turns it into
+     * string.
+     */
     if (error->code == error_none) {
         shell_read_quoted_arg(shell, error);
     }
-
     if (error->code == error_none) {
         shell_read_end(shell, error);
     }
-
     if (error->code == error_none) {
         strbuf_make_cstr(shell->buf, error);
     }
 
+    /* Initializes the query buffer with fixed capacity as N. */
     if (error->code == error_none) {
         if (converted > shell->database->movies.length) {
             count = shell->database->movies.length;
@@ -43,6 +48,7 @@ bool shell_run_topn(struct shell *restrict shell, struct error *restrict error)
         topn_query_init(&query_buf, count, error);
     }
 
+    /* Checks the error code and if OK executes the query. */
     switch (error->code) {
         case error_none:
             topn_query(shell->database,