Added support for stdin for todo add

This accepts one line as one task.

Also added some comments.

1 files changed, 13 insertions, 7 deletions

diff --git a/src/todo.c b/src/todo.c
index c7f416f..e56f8f5 100644
--- a/src/todo.c
+++ b/src/todo.c
@@ -72,6 +72,8 @@ static void process_todo_file(void (*mapper_func)(char *),
     }
   }
 
+  // i keeps track of the line in the file we are on.
+  // j is the index of mapped_indices[] that we are currently waiting for.
   for (size_t i = 1, j = 0;
        (line_len = getline(&line, &line_buff_size, todo_file)) >= 0; i++) {
     if (line_len > 5) {
@@ -121,15 +123,18 @@ static void print_list(char *line, ssize_t line_len, FILE *ignored,
 void todo_list(void) { process_todo_file(NULL, NULL, 0, print_list, false); }
 
 void todo_add(int argc, char **argv) {
-  if (argc < 1) {
-    fprintf(stderr, "todo add takes at least 1 argument\n");
-    exit(EXIT_FAILURE);
-  }
-
   open_todo_file("a");
 
-  for (int i = 0; i < argc; i++) {
-    fprintf(todo_file, "[ ] %s\n", argv[i]);
+  if (argc < 1) {
+    char *line = NULL;
+    size_t line_buff_size = 0;
+    while (getline(&line, &line_buff_size, stdin) > 0) {
+      fprintf(todo_file, "[ ] %s", line);
+    }
+  } else {
+    for (int i = 0; i < argc; i++) {
+      fprintf(todo_file, "[ ] %s\n", argv[i]);
+    }
   }
 
   fclose(todo_file);
@@ -230,6 +235,7 @@ void todo_sort(void) {
 
   pid_t pid = fork();
 
+  // The same as `LC_ALL=C sort < TODO > .TODO` from a shell.
   if (pid == 0) {
     open_todo_file("r");
     int input_fd = fileno(todo_file);