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

1 files changed, 22 insertions, 18 deletions

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]"