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

2 files changed, 61 insertions, 38 deletions

diff --git a/coreutils/Config.in b/coreutils/Config.in
index 4138390..29b55d4 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 9cb328a..fd25023 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;
 }