view lib/llist.c @ 912:f4f5132d5ac7

Stat cleanup. From the mailing list: Ok, first thing: clean up the help text. I realize what's there is copied verbatim from the man page, but that man page sucks. ("modification time" vs "change time"?) Took a bit of finagling to fit it in 80x24, but just made it. GLOBALS() indent was still tab, change to two spaces. And I tend to put a blank line between options lib/args.c automatically fills out and normal globals. We never do anything with date_stat_format() but immediately print it, might as well make the function do it. The types[] array in do_stat() is a rough edge. Hmmm... there's no else case that sets the type in case it was unknown (such as 0). In theory, this never happens. In practice it means I can cheat slightly, given this observation: $ find linux -name stat.h | xargs grep 'S_IF[A-Z]*[ \t]' linux/include/uapi/linux/stat.h:#define S_IFMT 00170000 linux/include/uapi/linux/stat.h:#define S_IFSOCK 0140000 linux/include/uapi/linux/stat.h:#define S_IFLNK 0120000 linux/include/uapi/linux/stat.h:#define S_IFREG 0100000 linux/include/uapi/linux/stat.h:#define S_IFBLK 0060000 linux/include/uapi/linux/stat.h:#define S_IFDIR 0040000 linux/include/uapi/linux/stat.h:#define S_IFCHR 0020000 linux/include/uapi/linux/stat.h:#define S_IFIFO 0010000 I.E. the only place the I_IFBLAH constants occur a stat.h header in current linux code is in the generic stuff, it doesn't vary per target. (The access permission bits are actually subtly standardized in posix due to the command line arguments to chmod, although I'm sure cygwin finds a way to break. But the type fields, not so much. But linux has to be binary compatible with itself foreverish, and that's all I really care about.) So, we have ALMOST have this going by twos, except there's no 8 and there is a 1. so let's make the 1 the default, feed a blank string into the 8... No, duh: octal. So it's actually 2, 4, 6, 8, 10, 12. So make the loop look like: filetype = statf->st_mode & S_IFMT; TT.ftname = types; for (i = 1; filetype != (i*8192) && i < 7; i++) TT.ftname += strlen(TT.ftname)+1; Yes that's linux-specific, and I think I'm ok with that. Printing all zeroes and pretending that's nanosecond resolution... either support it or don't. Let's see, supporting it is stat->st_atim.tv_nsec and similar... no mention of nanoseconds in strftime() (et tu, posix2008?) so pass it as a second argument and append it by hand... (Need to test that against musl...) When we hit an unknown type in print_it() we print the literal character, which is right for %% but what about an unknown option? $ stat -c %q / ? Eh, I guess that's a "don't care". It didn't die with an error, that's the important thing. I have a horrible idea for compressing the switch/case blocks, but should probably check this in and get some sleep for right now...
author Rob Landley <rob@landley.net>
date Tue, 28 May 2013 00:28:45 -0500
parents 50d759f8b371
children ef72a16f4b3a
line wrap: on
line source

/* llist.c - Linked list functions
 *
 * Linked list structures have a next pointer as their first element.
 */

#include "toys.h"

// Call a function (such as free()) on each element of a linked list.
void llist_traverse(void *list, void (*using)(void *data))
{
  void *old = list;

  while (list) {
    void *pop = llist_pop(&list);
    using(pop);

    // End doubly linked list too.
    if (old == list) break;
  }
}

// Return the first item from the list, advancing the list (which must be called
// as &list)
void *llist_pop(void *list)
{
  // I'd use a void ** for the argument, and even accept the typecast in all
  // callers as documentation you need the &, except the stupid compiler
  // would then scream about type-punned pointers.  Screw it.
  void **llist = (void **)list;
  void **next = (void **)*llist;
  *llist = *next;

  return (void *)next;
}

void dlist_add_nomalloc(struct double_list **list, struct double_list *new)
{
  if (*list) {
    new->next = *list;
    new->prev = (*list)->prev;
    (*list)->prev->next = new;
    (*list)->prev = new;
  } else *list = new->next = new->prev = new;
}


// Add an entry to the end of a doubly linked list
struct double_list *dlist_add(struct double_list **list, char *data)
{
  struct double_list *new = xmalloc(sizeof(struct double_list));

  new->data = data;
  dlist_add_nomalloc(list, new);

  return new;
}