Any comments are highly appreciated :)
>From 42074179d48dd9b84c120cb849a6a8e23f96f943 Mon Sep 17 00:00:00 2001
From: sin <s...@2f30.org>
Date: Wed, 16 Oct 2013 16:58:52 +0100
Subject: [PATCH] Add primitive du(1)
Defaults to a 512-byte blocksize.
---
Makefile | 1 +
du.1 | 18 ++++++++++
du.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 142 insertions(+)
create mode 100644 du.1
create mode 100644 du.c
diff --git a/Makefile b/Makefile
index 1cd6fbb..326cae8 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,7 @@ SRC = \
cut.c \
date.c \
dirname.c \
+ du.c \
echo.c \
env.c \
expand.c \
diff --git a/du.1 b/du.1
new file mode 100644
index 0000000..a5046e1
--- /dev/null
+++ b/du.1
@@ -0,0 +1,18 @@
+.TH DU 1 sbase\-VERSION
+.SH NAME
+du \- display disk usage statistics
+.SH SYNOPSIS
+.B du
+.RB [ \-a ]
+.RI [ file ...]
+.SH DESCRIPTION
+.B du
+displays the file system block usage for each
+.I file
+argument and for each directory in the file hierarchy rooted in directory
argument.
+If no file is specified, the block usage of the hierarchy rooted in the current
+directory is displayed.
+.SH OPTIONS
+.TP
+.BI \-a
+Display an entry for each file in the file hierarchy.
diff --git a/du.c b/du.c
new file mode 100644
index 0000000..5e33dec
--- /dev/null
+++ b/du.c
@@ -0,0 +1,123 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <limits.h>
+#include "util.h"
+
+static long blksize = 512;
+
+static bool aflag = false;
+
+static long du(const char *);
+static void usage(void);
+
+int
+main(int argc, char *argv[])
+{
+ char *bsize;
+
+ ARGBEGIN {
+ case 'a':
+ aflag = true;
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ bsize = getenv("BLOCKSIZE");
+ if (bsize)
+ blksize = estrtol(bsize, 0);
+
+ if (argc < 1) {
+ du(".");
+ } else {
+ for (; argc > 0; argc--, argv++)
+ du(argv[0]);
+ }
+ return EXIT_SUCCESS;
+}
+
+static char *
+push(const char *path)
+{
+ char *cwd;
+
+ cwd = agetcwd();
+ if (chdir(path) < 0)
+ eprintf("chdir %s:", path);
+ return cwd;
+}
+
+static void
+pop(char *path)
+{
+ if (chdir(path) < 0)
+ eprintf("chdir %s:", path);
+ free(path);
+}
+
+static void
+print(long n, char *path)
+{
+ printf("%lu\t%s\n", n, path);
+ free(path);
+}
+
+static long
+du(const char *path)
+{
+ DIR *dirp;
+ char *cwd;
+ struct dirent *dent;
+ struct stat st;
+ long n = 0, m;
+
+ if (lstat(path, &st) < 0)
+ eprintf("stat: %s:", path);
+ n = 512 * st.st_blocks / blksize;
+
+ switch (st.st_mode & S_IFMT) {
+ case S_IFDIR:
+ dirp = opendir(path);
+ if (!dirp) {
+ fprintf(stderr, "opendir: %s: %s\n", path,
+ strerror(errno));
+ break;
+ }
+ cwd = push(path);
+ while ((dent = readdir(dirp))) {
+ if (strcmp(dent->d_name, ".") == 0 ||
+ strcmp(dent->d_name, "..") == 0)
+ continue;
+ if (lstat(dent->d_name, &st) < 0)
+ eprintf("stat: %s:", dent->d_name);
+ if (S_ISDIR(st.st_mode)) {
+ n += du(dent->d_name);
+ } else {
+ m = 512 * st.st_blocks / blksize;
+ n += m;
+ if (aflag)
+ print(m, realpath(dent->d_name, NULL));
+ }
+ }
+ pop(cwd);
+ closedir(dirp);
+ break;
+ }
+
+ print(n, realpath(path, NULL));
+ return n;
+}
+
+void
+usage(void)
+{
+ eprintf("usage: %s [-a] [file...]\n", argv0);
+}
--
1.8.3.4
