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, 58 insertions, 35 deletions

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;
 }