df: add support for more options, add some coreutils 6.10 compat.

 by Bernhard Reutner-Fischer

function                                             old     new   delta
df_main                                              664     795    +131
packed_usage                                       24812   24862     +50
make_human_readable_str                              213     262     +49
static.ignored_mounts                                  -       8      +8
static.unit_chars                                      -       7      +7
static.zero_and_units                                  6       -      -6
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 3/0 up/down: 245/-6)            Total: 239 bytes

5 files changed, 105 insertions, 69 deletions

diff --git a/coreutils/Config.in b/coreutils/Config.in
index 413839035..29b55d4ec 100644
--- a/coreutils/Config.in
+++ b/coreutils/Config.in
@@ -136,12 +136,12 @@ config DF
 	  df reports the amount of disk space used and available
 	  on filesystems.
 
-config FEATURE_DF_INODE
-	bool "Enable -i (inode information)"
+config FEATURE_DF_FANCY
+	bool "Enable -a, -i, -B"
 	default n
 	depends on DF
 	help
-	  This option enables support for df -i.
+	  This option enables -a, -i and -B.
 
 config DIRNAME
 	bool "dirname"
diff --git a/coreutils/df.c b/coreutils/df.c
index 9cb328aa3..fd2502309 100644
--- a/coreutils/df.c
+++ b/coreutils/df.c
@@ -8,7 +8,7 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-/* BB_AUDIT SUSv3 _NOT_ compliant -- options -P and -t missing.  Also blocksize. */
+/* BB_AUDIT SUSv3 _NOT_ compliant -- option -t missing. */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/df.html */
 
 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
@@ -16,6 +16,10 @@
  * Size reduction.  Removed floating point dependency.  Added error checking
  * on output.  Output stats on 0-sized filesystems if specifically listed on
  * the command line.  Properly round *-blocks, Used, and Available quantities.
+ *
+ * Aug 28, 2008      Bernhard Reutner-Fischer
+ *
+ * Implement -P and -B; better coreutils compat; cleanup
  */
 
 #include <mntent.h>
@@ -34,51 +38,73 @@ int df_main(int argc, char **argv)
 {
 	unsigned long blocks_used;
 	unsigned blocks_percent_used;
-#if ENABLE_FEATURE_HUMAN_READABLE
-	unsigned df_disp_hr = 1024;
-#endif
+	unsigned long df_disp_hr = 1024;
 	int status = EXIT_SUCCESS;
 	unsigned opt;
 	FILE *mount_table;
 	struct mntent *mount_entry;
 	struct statfs s;
-	/* default display is kilobytes */
-	const char *disp_units_hdr = "1k-blocks";
+	static const char ignored_mounts[] ALIGN1 =
+	  "rootfs\0";
 
 	enum {
-		OPT_ALL = (1 << 0),
-		OPT_INODE = (ENABLE_FEATURE_HUMAN_READABLE ? (1 << 4) : (1 << 2))
-		            * ENABLE_FEATURE_DF_INODE
+		OPT_KILO  = (1 << 0),
+		OPT_POSIX = (1 << 1),
+		OPT_ALL   = (1 << 2) * ENABLE_FEATURE_DF_FANCY,
+		OPT_INODE = (1 << 3) * ENABLE_FEATURE_DF_FANCY,
+		OPT_BSIZE = (1 << 4) * ENABLE_FEATURE_DF_FANCY,
+		OPT_HUMAN = (1 << 5) * ENABLE_FEATURE_HUMAN_READABLE,
+		OPT_MEGA  = (1 << 6) * ENABLE_FEATURE_HUMAN_READABLE,
 	};
+	const char *disp_units_hdr = NULL;
+	char *chp;
 
-#if ENABLE_FEATURE_HUMAN_READABLE
-	opt_complementary = "h-km:k-hm:m-hk";
-	opt = getopt32(argv, "ahmk" USE_FEATURE_DF_INODE("i"));
-	if (opt & (1 << 1)) { // -h
+#if ENABLE_FEATURE_HUMAN_READABLE && ENABLE_FEATURE_DF_FANCY
+	opt_complementary = "k-mB:m-Bk:B-km";
+#elif ENABLE_FEATURE_HUMAN_READABLE
+	opt_complementary = "k-m:m-k";
+#endif
+	opt = getopt32(argv, "kP"
+			USE_FEATURE_DF_FANCY("aiB:")
+			USE_FEATURE_HUMAN_READABLE("hm")
+			USE_FEATURE_DF_FANCY(, &chp));
+	if (opt & OPT_MEGA)
+		df_disp_hr = 1024*1024;
+
+	if (opt & OPT_BSIZE)
+		df_disp_hr = xatoul_range(chp, 1, ULONG_MAX); /* disallow 0 */
+
+	/* From the manpage of df from coreutils-6.10:
+	   Disk space is shown in 1K blocks by default, unless the environment
+	   variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.
+	*/
+	if (getenv("POSIXLY_CORRECT")) /* TODO - a new libbb function? */
+		df_disp_hr = 512;
+
+	if (opt & OPT_HUMAN) {
 		df_disp_hr = 0;
 		disp_units_hdr = "     Size";
 	}
-	if (opt & (1 << 2)) { // -m
-		df_disp_hr = 1024*1024;
-		disp_units_hdr = "1M-blocks";
-	}
-	if (opt & OPT_INODE) {
+	if (opt & OPT_INODE)
 		disp_units_hdr = "   Inodes";
-	}
+
+	if (disp_units_hdr == NULL) {
+#if ENABLE_FEATURE_HUMAN_READABLE
+		disp_units_hdr = xasprintf("%s-blocks",
+			make_human_readable_str(df_disp_hr, 0, !!(opt & OPT_POSIX)));
 #else
-	opt = getopt32(argv, "ak" USE_FEATURE_DF_INODE("i"));
+		disp_units_hdr = xasprintf("%d-blocks", df_disp_hr);
 #endif
-
-	printf("Filesystem           %-15sUsed Available Use%% Mounted on\n",
-			disp_units_hdr);
+	}
+	printf("Filesystem           %-15sUsed Available %s Mounted on\n",
+			disp_units_hdr, (opt & OPT_POSIX) ? "Capacity" : "Use%");
 
 	mount_table = NULL;
 	argv += optind;
 	if (optind >= argc) {
 		mount_table = setmntent(bb_path_mtab_file, "r");
-		if (!mount_table) {
+		if (!mount_table)
 			bb_perror_msg_and_die(bb_path_mtab_file);
-		}
 	}
 
 	while (1) {
@@ -93,9 +119,8 @@ int df_main(int argc, char **argv)
 			}
 		} else {
 			mount_point = *argv++;
-			if (!mount_point) {
+			if (!mount_point)
 				break;
-			}
 			mount_entry = find_mount_point(mount_point, bb_path_mtab_file);
 			if (!mount_entry) {
 				bb_error_msg("%s: can't find mount point", mount_point);
@@ -118,10 +143,9 @@ int df_main(int argc, char **argv)
 				s.f_blocks = s.f_files;
 				s.f_bavail = s.f_bfree = s.f_ffree;
 				s.f_bsize = 1;
-#if ENABLE_FEATURE_HUMAN_READABLE
+
 				if (df_disp_hr)
 					df_disp_hr = 1;
-#endif
 			}
 			blocks_used = s.f_blocks - s.f_bfree;
 			blocks_percent_used = 0;
@@ -131,11 +155,10 @@ int df_main(int argc, char **argv)
 						) / (blocks_used + s.f_bavail);
 			}
 
-#ifdef WHY_IT_SHOULD_BE_HIDDEN
-			if (strcmp(device, "rootfs") == 0) {
+			/* GNU coreutils 6.10 skip certain mounts, try to be compatible.  */
+			if (index_in_strings(device, ignored_mounts) != -1)
 				continue;
-			}
-#endif
+
 #ifdef WHY_WE_DO_IT_FOR_DEV_ROOT_ONLY
 /* ... and also this is the only user of find_block_device */
 			if (strcmp(device, "/dev/root") == 0) {
@@ -164,12 +187,12 @@ int df_main(int argc, char **argv)
 #else
 			printf(" %9lu %9lu %9lu %3u%% %s\n",
 					kscale(s.f_blocks, s.f_bsize),
-					kscale(s.f_blocks-s.f_bfree, s.f_bsize),
+					kscale(s.f_blocks - s.f_bfree, s.f_bsize),
 					kscale(s.f_bavail, s.f_bsize),
 					blocks_percent_used, mount_point);
 #endif
 		}
 	}
 
-	fflush_stdout_and_exit(status);
+	return status;
 }
diff --git a/include/usage.h b/include/usage.h
index 41012afc1..a09f7eac2 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -705,36 +705,40 @@
      "\n		do not poll for events" \
 	)
 
-/* -k is accepted but ignored for !HUMAN_READABLE,
- * but we won't mention this (unimportant) */
-#if ENABLE_FEATURE_HUMAN_READABLE || ENABLE_FEATURE_DF_INODE
-#define DF_HAS_OPTIONS(x) x
-#else
-#define DF_HAS_OPTIONS(x)
-#endif
 #define df_trivial_usage \
-	DF_HAS_OPTIONS("[-") \
-	USE_FEATURE_HUMAN_READABLE("hmk") USE_FEATURE_DF_INODE("i") \
-	DF_HAS_OPTIONS("] ") "[FILESYSTEM...]"
+	"[-Pk" \
+	USE_FEATURE_HUMAN_READABLE("mh") \
+	USE_FEATURE_DF_FANCY("ai] [-B SIZE") \
+	"] [FILESYSTEM...]"
 #define df_full_usage "\n\n" \
        "Print filesystem usage statistics\n" \
-	DF_HAS_OPTIONS("\nOptions:") \
+     "\nOptions:" \
+     "\n	-P	POSIX output format" \
+     "\n	-k	1024-byte blocks (default)" \
 	USE_FEATURE_HUMAN_READABLE( \
+     "\n	-m	1M-byte blocks" \
      "\n	-h	Human readable (e.g. 1K 243M 2G)" \
-     "\n	-m	1024*1024 blocks" \
-     "\n	-k	1024 blocks" \
 	) \
-	USE_FEATURE_DF_INODE( \
+	USE_FEATURE_DF_FANCY( \
+     "\n	-a	Show all filesystems" \
      "\n	-i	Inodes" \
-	)
+     "\n	-B SIZE	Blocksize" \
+	) \
+
 #define df_example_usage \
        "$ df\n" \
-       "Filesystem           1k-blocks      Used Available Use% Mounted on\n" \
+       "Filesystem           1K-blocks      Used Available Use% Mounted on\n" \
        "/dev/sda3              8690864   8553540    137324  98% /\n" \
        "/dev/sda1                64216     36364     27852  57% /boot\n" \
        "$ df /dev/sda3\n" \
-       "Filesystem           1k-blocks      Used Available Use% Mounted on\n" \
-       "/dev/sda3              8690864   8553540    137324  98% /\n"
+       "Filesystem           1K-blocks      Used Available Use% Mounted on\n" \
+       "/dev/sda3              8690864   8553540    137324  98% /\n" \
+       "$ POSIXLY_CORRECT=sure df /dev/sda3\n" \
+       "Filesystem         512B-blocks      Used Available Use% Mounted on\n" \
+       "/dev/sda3             17381728  17107080    274648  98% /\n" \
+       "$ POSIXLY_CORRECT=yep df -P /dev/sda3\n" \
+       "Filesystem          512-blocks      Used Available Capacity Mounted on\n" \
+       "/dev/sda3             17381728  17107080    274648      98% /\n"
 
 #define dhcprelay_trivial_usage \
        "[client1,client2,...] [server_device]"
diff --git a/libbb/human_readable.c b/libbb/human_readable.c
index dad26edcf..61c856750 100644
--- a/libbb/human_readable.c
+++ b/libbb/human_readable.c
@@ -32,7 +32,9 @@ const char* FAST_FUNC make_human_readable_str(unsigned long long size,
 	unsigned long block_size, unsigned long display_unit)
 {
 	/* The code will adjust for additional (appended) units */
-	static const char zero_and_units[] ALIGN1 = { '0', 0, 'k', 'M', 'G', 'T' };
+	static const char unit_chars[] ALIGN1 = {
+		'\0', 'K', 'M', 'G', 'T', 'P', 'E'
+	};
 	static const char fmt[] ALIGN1 = "%llu";
 	static const char fmt_tenths[] ALIGN1 = "%llu.%d%c";
 
@@ -42,26 +44,33 @@ const char* FAST_FUNC make_human_readable_str(unsigned long long size,
 	int frac;
 	const char *u;
 	const char *f;
+	smallint no_tenths;
 
-	u = zero_and_units;
-	f = fmt;
-	frac = 0;
+	if (size == 0)
+		return "0";
 
-	val = size * block_size;
-	if (val == 0) {
-		return u;
+	/* If block_size is 0 then do not print tenths */
+	no_tenths = 0;
+	if (block_size == 0) {
+		no_tenths = 1;
+		block_size = 1;
 	}
 
+	u = unit_chars;
+	val = size * block_size;
+	f = fmt;
+	frac = 0;
+
 	if (display_unit) {
 		val += display_unit/2;	/* Deal with rounding */
 		val /= display_unit;	/* Don't combine with the line above!!! */
+		/* will just print it as ulonglong (below) */
 	} else {
-		++u;
 		while ((val >= 1024)
-		 && (u < zero_and_units + sizeof(zero_and_units) - 1)
+		 && (u < unit_chars + sizeof(unit_chars) - 1)
 		) {
 			f = fmt_tenths;
-			++u;
+			u++;
 			frac = (((int)(val % 1024)) * 10 + 1024/2) / 1024;
 			val /= 1024;
 		}
@@ -69,9 +78,9 @@ const char* FAST_FUNC make_human_readable_str(unsigned long long size,
 			++val;
 			frac = 0;
 		}
-#if 0
+#if 1
 		/* Sample code to omit decimal point and tenths digit. */
-		if (/* no_tenths */ 1) {
+		if (no_tenths) {
 			if (frac >= 5) {
 				++val;
 			}
diff --git a/scripts/defconfig b/scripts/defconfig
index 686974b74..96c1978ff 100644
--- a/scripts/defconfig
+++ b/scripts/defconfig
@@ -153,7 +153,7 @@ CONFIG_DD=y
 CONFIG_FEATURE_DD_SIGNAL_HANDLING=y
 CONFIG_FEATURE_DD_IBS_OBS=y
 CONFIG_DF=y
-CONFIG_FEATURE_DF_INODE=y
+CONFIG_FEATURE_DF_FANCY=y
 CONFIG_DIRNAME=y
 CONFIG_DOS2UNIX=y
 CONFIG_UNIX2DOS=y