du: add --inodes option

This new option can be used to find directories with a huge
amount of files.  The GNU find utility has the printf format
"%h" which prints the number of entries in a directory, but
this is non-cumulative and doesn't handle hard links.

* src/du.c (struct duinfo): Add new member for counting inodes.
(duinfo_init): Initialize inodes member with Zero.
(duinfo_set): Set inodes counter to 1.
(duinfo_add): Sum up the 2 given inodes counters.
(opt_inodes): Add new boolean flag to remember if the --inodes
option has been specified.
(INODES_OPTION): Add new enum value to be used ...
(long_options): ... here.
(usage): Add description of the new option.
(print_size): Pass inodes counter or size to print_only_size,
depending on the inodes mode.
(process_file): Adapt threshold handling: with --inodes, print or
elide the entries according to the struct member inodes.
(main): Add a case for accepting the new INODES_OPTION.
Print a warning diagnostic when --inodes is used together with the
option --apparent-size or -b.
Reset the output_block_size to 1 ... and thus ignoring the
options -m and -k.
* tests/du/inodes.sh: Add a new test.
* tests/local.mk (all_tests): Mention it.
* doc/coreutils.texi (du invocation): Document the new option.
* NEWS: Mention the new option.

1 files changed, 34 insertions, 4 deletions

diff --git a/src/du.c b/src/du.c
index a6fa16b29..9f1f98c5c 100644
--- a/src/du.c
+++ b/src/du.c
@@ -78,6 +78,9 @@ struct duinfo
   /* Size of files in directory.  */
   uintmax_t size;
 
+  /* Number of inodes in directory.  */
+  uintmax_t inodes;
+
   /* Latest time stamp found.  If tmax.tv_sec == TYPE_MINIMUM (time_t)
      && tmax.tv_nsec < 0, no time stamp has been found.  */
   struct timespec tmax;
@@ -88,6 +91,7 @@ static inline void
 duinfo_init (struct duinfo *a)
 {
   a->size = 0;
+  a->inodes = 0;
   a->tmax.tv_sec = TYPE_MINIMUM (time_t);
   a->tmax.tv_nsec = -1;
 }
@@ -97,6 +101,7 @@ static inline void
 duinfo_set (struct duinfo *a, uintmax_t size, struct timespec tmax)
 {
   a->size = size;
+  a->inodes = 1;
   a->tmax = tmax;
 }
 
@@ -106,6 +111,7 @@ duinfo_add (struct duinfo *a, struct duinfo const *b)
 {
   uintmax_t sum = a->size + b->size;
   a->size = a->size <= sum ? sum : UINTMAX_MAX;
+  a->inodes = a->inodes + b->inodes;
   if (timespec_cmp (a->tmax, b->tmax) < 0)
     a->tmax = b->tmax;
 }
@@ -154,6 +160,9 @@ static intmax_t opt_threshold = 0;
 /* Human-readable options for output.  */
 static int human_output_opts;
 
+/* Output inodes count instead of blocks used.  */
+static bool opt_inodes = false;
+
 /* If true, print most recently modified date, using the specified format.  */
 static bool opt_time = false;
 
@@ -197,7 +206,8 @@ enum
   HUMAN_SI_OPTION,
   FTS_DEBUG,
   TIME_OPTION,
-  TIME_STYLE_OPTION
+  TIME_STYLE_OPTION,
+  INODES_OPTION
 };
 
 static struct option const long_options[] =
@@ -214,6 +224,7 @@ static struct option const long_options[] =
   {"exclude-from", required_argument, NULL, 'X'},
   {"files0-from", required_argument, NULL, FILES0_FROM_OPTION},
   {"human-readable", no_argument, NULL, 'h'},
+  {"inodes", no_argument, NULL, INODES_OPTION},
   {"si", no_argument, NULL, HUMAN_SI_OPTION},
   {"max-depth", required_argument, NULL, 'd'},
   {"null", no_argument, NULL, '0'},
@@ -306,6 +317,7 @@ Summarize disk usage of each FILE, recursively for directories.\n\
   -H                    equivalent to --dereference-args (-D)\n\
   -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)\
 \n\
+      --inodes          list inode usage information instead of block usage\n\
 "), stdout);
       fputs (_("\
   -k                    like --block-size=1K\n\
@@ -394,7 +406,10 @@ print_only_size (uintmax_t n_bytes)
 static void
 print_size (const struct duinfo *pdui, const char *string)
 {
-  print_only_size (pdui->size);
+  print_only_size (opt_inodes
+                   ? pdui->inodes
+                   : pdui->size);
+
   if (opt_time)
     {
       putchar ('\t');
@@ -589,9 +604,10 @@ process_file (FTS *fts, FTSENT *ent)
       || level == 0)
     {
       /* Print or elide this entry according to the --threshold option.  */
+      uintmax_t v = opt_inodes ? dui_to_print.inodes : dui_to_print.size;
       if (opt_threshold < 0
-          ? dui_to_print.size <= -opt_threshold
-          : dui_to_print.size >= opt_threshold)
+          ? v <= -opt_threshold
+          : v >= opt_threshold)
         print_size (&dui_to_print, file);
     }
 
@@ -853,6 +869,10 @@ main (int argc, char **argv)
           add_exclude (exclude, optarg, EXCLUDE_WILDCARDS);
           break;
 
+        case INODES_OPTION:
+          opt_inodes = true;
+          break;
+
         case TIME_OPTION:
           opt_time = true;
           time_type =
@@ -899,6 +919,16 @@ main (int argc, char **argv)
   if (opt_summarize_only)
     max_depth = 0;
 
+  if (opt_inodes)
+    {
+      if (apparent_size)
+        {
+          error (0, 0, _("warning: options --apparent-size and -b are "
+                         "ineffective with --inodes"));
+        }
+      output_block_size = 1;
+    }
+
   /* Process time style if printing last times.  */
   if (opt_time)
     {