sbase/du.c
remph e8fe04c543 du: Dedup hardlinks
Conform to POSIX, which says `Files with multiple links shall be counted
and written for only one entry,' in the 2008[1] and 2013[2] editions, and
uses more words to say the same thing in the 2017[3] and 2024[4] editions.
This patch also keeps inodes between operands and dedups symlinks if
applicable, which are implementation-defined in 2017 and required in 2024.
See also the `RATIONALE' section in the 2024 edition.

[1] https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/utilities/du.html
[2] https://pubs.opengroup.org/onlinepubs/9699919799.2013edition/utilities/du.html
[3] https://pubs.opengroup.org/onlinepubs/9699919799/utilities/du.html
[4] https://pubs.opengroup.org/onlinepubs/9799919799/utilities/du.html
2025-03-19 21:51:05 +01:00

168 lines
2.8 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <search.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "fs.h"
#include "util.h"
static size_t maxdepth = SIZE_MAX;
static size_t blksize = 512;
static int aflag = 0;
static int sflag = 0;
static int hflag = 0;
struct file {
dev_t devno;
ino_t inode;
};
static void
printpath(off_t n, const char *path)
{
if (hflag)
printf("%s\t%s\n", humansize(n * blksize), path);
else
printf("%jd\t%s\n", (intmax_t)n, path);
}
static off_t
nblks(blkcnt_t blocks)
{
return (512 * blocks + blksize - 1) / blksize;
}
static int
cmp(const void *p1, const void *p2)
{
const struct file *f1 = p1, *f2 = p2;
if (f1->devno > f2->devno)
return -1;
if (f1->devno < f2->devno)
return 1;
/* f1->devno == f2->devno */
if (f1->inode < f2->inode)
return -1;
if (f1->inode > f2->inode)
return 1;
return 0;
}
static int
duplicated(dev_t dev, ino_t ino)
{
static void *tree;
struct file **fpp, *fp, file = {dev, ino};
if ((fpp = tsearch(&file, &tree, cmp)) == NULL)
eprintf("%s:", argv0);
if (*fpp != &file)
return 1;
/* new file added */
fp = emalloc(sizeof(*fp));
*fp = file;
*fpp = fp;
return 0;
}
static void
du(int dirfd, const char *path, struct stat *st, void *data, struct recursor *r)
{
off_t *total = data, subtotal;
subtotal = nblks(st->st_blocks);
if (S_ISDIR(st->st_mode)) {
recurse(dirfd, path, &subtotal, r);
} else if (r->follow != 'P' || st->st_nlink > 1) {
if (duplicated(st->st_dev, st->st_ino))
goto print;
}
*total += subtotal;
print:
if (!r->depth)
printpath(*total, r->path);
else if (!sflag && r->depth <= maxdepth && (S_ISDIR(st->st_mode) || aflag))
printpath(subtotal, r->path);
}
static void
usage(void)
{
eprintf("usage: %s [-a | -s] [-d depth] [-h] [-k] [-H | -L | -P] [-x] [file ...]\n", argv0);
}
int
main(int argc, char *argv[])
{
struct recursor r = { .fn = du, .follow = 'P' };
off_t n = 0;
int kflag = 0, dflag = 0;
char *bsize;
ARGBEGIN {
case 'a':
aflag = 1;
break;
case 'd':
dflag = 1;
maxdepth = estrtonum(EARGF(usage()), 0, MIN(LLONG_MAX, SIZE_MAX));
break;
case 'h':
hflag = 1;
break;
case 'k':
kflag = 1;
break;
case 's':
sflag = 1;
break;
case 'x':
r.flags |= SAMEDEV;
break;
case 'H':
case 'L':
case 'P':
r.follow = ARGC();
break;
default:
usage();
} ARGEND
if ((aflag && sflag) || (dflag && sflag))
usage();
bsize = getenv("BLOCKSIZE");
if (bsize)
blksize = estrtonum(bsize, 1, MIN(LLONG_MAX, SIZE_MAX));
if (kflag)
blksize = 1024;
if (!argc) {
recurse(AT_FDCWD, ".", &n, &r);
} else {
for (; *argv; argc--, argv++) {
n = 0;
recurse(AT_FDCWD, *argv, &n, &r);
}
}
return fshut(stdout, "<stdout>") || recurse_status;
}