Re: Suggested enhancement to du command - show last modified date.

[Paul Eggert]

Jim Meyering <address@hidden> writes:

> Thank you for the patch.
> I've applied it

Yes, it's a nice thing to add.  Thanks too.

I reviewed the patch and have some more ideas, which I installed as
follows.  One more thing (which I didn't do yet) is that there's a
reasonable amount of code duplication between ls, du, and date, and it
should be refactored at some point.  I see you've got a FIXME about
that already....

2005-06-23  Paul Eggert  <address@hidden>

        Address the following "du" issues:

        - The option name "--last-time=TYPE" is different from the ls's option
          "--time=TYPE" with a similar meaning.  I assume this wasn't intended.

        - --time-style implies --time, but this is not true for "ls".  It's
          better to be consistent.

        - Since we don't have POSIX compatibility concerns, there's no need
          for the "posix-" styles, or for support of styles with newlines, or
          for the "locale" style, except for parsing the TIME_STYLE
          environment variable.

        - It's cleaner (and these days, no less efficient) to use functions
          rather than macros when possible.

        - struct duinfo doesn't need a 'valid' flag; you can simply use a time
          stamp that is less than all valid time stamps.

        - The code needs a bit of reformatting to fit the usual GNU style.

        * NEWS: du's --last-time option is now --time.
        * doc/coreutils.texi (ls invocation): Fix typo: --time=use is
        equivalent to --time=atime, not --time=ctime.
        (ls invocation, du invocation): Fix typo: --time-style=long-iso
        is equivalent to a time style with a leading "+".
        (du invocation): --last-time is now --time.
        --time-style no longer implies --time.
        The locale and posix- stuff now works only for TIME_STYLE, not
        for --time-style.  Give equivalent format for --time-style=iso.
        * src/du.c: Do not include hard-locale.h.
        (struct duinfo): Remove 'valid' member.  All uses changed to use
        negative nsec instead.
        (DUIINFO_INI, DUINFO_SET, DUINFO_ADD): Remove.
        (duinfo_init, duinfo_set, duinfo_add): New functions, taking the
        role of the removed macros.
        (opt_time): Renamed from opt_last_time.  All uses changed.
        (TIME_OPTION): Renamed from LAST_TIME_OPTION.  All uses changed.
        (long_options, usage): Rename --last-time to --time.
        (locale_time_style): Remove.
        (time_style_args, time_style_types, usage): Remove support for
        --time-style=locale.
        (show_date): Now returns void, since nobody looked at the result.
        Assume FORMAT is not null.  An empty FORMAT now outputs an empty time.
        Simplify nstrftime invocation.
        (main): Put in ls compatibility workarounds only for TIME_STYLE,
        not for --time-style.  Omit unnecessary space in iso time style.

Index: NEWS
===================================================================
RCS file: /fetish/cu/NEWS,v
retrieving revision 1.298
diff -p -u -r1.298 NEWS
--- NEWS        23 Jun 2005 14:47:27 -0000      1.298
+++ NEWS        23 Jun 2005 22:24:38 -0000
@@ -151,7 +151,7 @@ GNU coreutils NEWS                      
   dd has new iflag= and oflag= flags "binary" and "text", which have an
   effect only on nonstandard platforms that distinguish text from binary I/O.
 
-  du accepts new options: --last-time[=TYPE] and --time-style=STYLE
+  du accepts new options: --time[=TYPE] and --time-style=STYLE
 
   join now supports a NUL field separator, e.g., "join -t '\0'".
   join now detects and reports incompatible options, e.g., "join -t x -t y",
Index: doc/coreutils.texi
===================================================================
RCS file: /fetish/cu/doc/coreutils.texi,v
retrieving revision 1.267
diff -p -u -r1.267 coreutils.texi
--- doc/coreutils.texi  23 Jun 2005 15:00:29 -0000      1.267
+++ doc/coreutils.texi  23 Jun 2005 22:24:40 -0000
@@ -5677,7 +5677,6 @@ it outputs.  By default, sorting is done
 @item -c
 @itemx --time=ctime
 @itemx --time=status
address@hidden --time=use
 @opindex -c
 @opindex --time
 @opindex address@hidden, printing or sorting by}
@@ -5724,6 +5723,7 @@ Sort by modification time (the @samp{mti
 @item -u
 @itemx --time=atime
 @itemx --time=access
address@hidden --time=use
 @opindex -u
 @opindex --time
 @opindex use address@hidden, printing or sorting files by}
@@ -6009,7 +6009,7 @@ uses the full timestamp to determine whe
 List @acronym{ISO} 8601 date and time in minutes, e.g.,
 @samp{2002-03-30 23:45}.  These timestamps are shorter than
 @samp{full-iso} timestamps, and are usually good enough for everyday
-work.  This style is equivalent to @samp{%Y-%m-%d %H:%M}.
+work.  This style is equivalent to @samp{+%Y-%m-%d %H:%M}.
 
 @item iso
 List @acronym{ISO} 8601 dates for non-recent timestamps (e.g.,
@@ -9004,30 +9004,6 @@ Dereference symbolic links (show the dis
 or directory that the link points to instead of the space used by
 the link).
 
address@hidden --last-time
address@hidden --last-time
address@hidden last modified dates, displaying in @command{du}
-Show time of the most recent modification of any file in the directory,
-or any of its subdirectories.
-
address@hidden --last-time=ctime
address@hidden --last-time=status
address@hidden --last-time=use
address@hidden --last-time
address@hidden address@hidden, show the most recent}
address@hidden status address@hidden, show the most recent}
address@hidden use address@hidden, show the most recent}
-Show the most recent status change time (the @samp{ctime} in the inode) of
-any file in the directory, instead of the modification time.
-
address@hidden --last-time=atime
address@hidden --last-time=access
address@hidden --last-time
address@hidden address@hidden, show the most recent}
address@hidden access address@hidden, show the most recent}
-Show the most recent access time (the @samp{atime} in the inode) of
-any file in the directory, instead of the modification time.
-
 @item -P
 @itemx --no-dereference
 @opindex -P
@@ -9073,12 +9049,35 @@ Display only a total for each argument.
 Report the size of each directory separately, not including the sizes
 of subdirectories.
 
address@hidden --time
address@hidden --time
address@hidden last modified dates, displaying in @command{du}
+Show time of the most recent modification of any file in the directory,
+or any of its subdirectories.
+
address@hidden --time=ctime
address@hidden --time=status
address@hidden --time=use
address@hidden --time
address@hidden address@hidden, show the most recent}
address@hidden status address@hidden, show the most recent}
address@hidden use address@hidden, show the most recent}
+Show the most recent status change time (the @samp{ctime} in the inode) of
+any file in the directory, instead of the modification time.
+
address@hidden --time=atime
address@hidden --time=access
address@hidden --time
address@hidden address@hidden, show the most recent}
address@hidden access address@hidden, show the most recent}
+Show the most recent access time (the @samp{atime} in the inode) of
+any file in the directory, instead of the modification time.
+
 @item address@hidden
 @opindex --time-style
 @cindex time style
-Implicity selects the option @option{--last-time} to show last modified
-date if an explicit @option{--last-time} option has not been selected.
-List timestamps in style @var{style}.  The @var{style} should
+List timestamps in style @var{style}.  This option has an effect only if
+the @option{--time} option is also specified.  The @var{style} should
 be one of the following:
 
 @table @samp
@@ -9101,49 +9100,21 @@ format with nanosecond precision, e.g., 
 List @acronym{ISO} 8601 date and time in minutes, e.g.,
 @samp{2002-03-30 23:45}.  These timestamps are shorter than
 @samp{full-iso} timestamps, and are usually good enough for everyday
-work.  This style is equivalent to @samp{%Y-%m-%d %H:%M}.
+work.  This style is equivalent to @samp{+%Y-%m-%d %H:%M}.
 
 @item iso
-List @acronym{ISO} 8601 dates for timestamps
-
address@hidden locale
address@hidden LC_TIME
-List timestamps in a locale-dependent form.  For example, a Finnish
-locale might list timestamps like @samp{maalis 30@ @ 2002}.
-Locale-dependent timestamps typically consume more space than @samp{iso}
-timestamps and are harder for programs to parse because locale
-conventions vary so widely, but they are easier for many people to read.
-
-The @env{LC_TIME} locale category specifies the timestamp format.  The
-default @acronym{POSIX} locale uses timestamps like @samp{Mar 30@
-@ 2002}; in this locale, the following two @command{du} invocations are
-equivalent:
-
address@hidden
-du --last-time --time-style="+%b %e %Y"
-du --last-time --time-style="locale"
address@hidden example
-
-Other locales behave differently.  For example, in a German locale,
address@hidden"locale"} might be equivalent to
address@hidden"+%e. %b %Y"}
-and might generate timestamps like @samp{30. M@"ar 2002@ }.
-
address@hidden address@hidden
address@hidden LC_TIME
-List @acronym{POSIX}-locale timestamps if the @env{LC_TIME} locale
-category is @acronym{POSIX}, @var{style} timestamps otherwise.  For
-example, the default style, which is @samp{posix-long-iso}, lists
-timestamps like @samp{Mar 30@ @ 2002} when in
-the @acronym{POSIX} locale, and like @samp{2002-03-30 23:45} otherwise.
+List @acronym{ISO} 8601 dates for timestamps, e.g., @samp{2002-03-30}.
+This style is equivalent to @samp{+%Y-%m-%d}.
 @end table
 
 @vindex TIME_STYLE
 You can specify the default value of the @option{--time-style} option
 with the environment variable @env{TIME_STYLE}; if @env{TIME_STYLE} is not set
-the default style is @samp{posix-long-iso}. If @env{TIME_STYLE} contains two
-styles, separated by a newline (for @command{ls}), the @command{du} uses only
-the first of the two styles.
+the default style is @samp{long-iso}.  For compatibility with @command{ls},
+if @env{TIME_STYLE} begins with @samp{+} and contains a newline,
+the newline and any later characters are ignored; if @env{TIME_STYLE}
+begins with @samp{posix-} the @samp{posix-} is ignored; and if
address@hidden is @samp{locale} it is ignored.
 
 @item -x
 @itemx --one-file-system
Index: src/du.c
===================================================================
RCS file: /fetish/cu/src/du.c,v
retrieving revision 1.209
diff -p -u -r1.209 du.c
--- src/du.c    23 Jun 2005 15:27:55 -0000      1.209
+++ src/du.c    23 Jun 2005 22:24:40 -0000
@@ -34,7 +34,6 @@
 #include "dirname.h" /* for strip_trailing_slashes */
 #include "error.h"
 #include "exclude.h"
-#include "hard-locale.h"
 #include "hash.h"
 #include "human.h"
 #include "inttostr.h"
@@ -81,43 +80,54 @@ static Hash_table *htab;
 
 struct duinfo
 {
-  uintmax_t size;    /* Size of files in directory */
-  time_t    dmax;    /* Last modified date */
-  int       nsec;    /* Nanoseconds part of date */
-  int       valid;   /* Indicates that date is valid */
+  /* Size of files in directory.  */
+  uintmax_t size;
+
+  /* Latest time stamp found.  If dmax == TYPE_MINIMUM (time_t) && nsec < 0,
+     no time stamp has been found.  */
+  time_t dmax;
+  int nsec;
 };
 
-/* DUINFO_INI (struct duinfo a); - Initialise duinfo structure. */
-#define DUINFO_INI(a) \
-  do { (a).size = 0; (a).dmax = 0; (a).nsec = 0; (a).valid = 0; } while (0)
-
-/* DUINFO_SET (struct duinfo a, uintmax_t size, time_t date, int nsec) - Set 
structure data. */
-#define DUINFO_SET(a, fsize, fdmax, fnsec)  \
-  do { (a).size = (fsize); (a).dmax = (fdmax); (a).nsec = fnsec; (a).valid = 
1; } while (0)
-
-/* DUINFO_ADD (struct duinfo a, const struct duinfo b) - Accumulate directory 
data. */
-#define DUINFO_ADD(a, b)  \
-  do {  if ( (b).valid ) \
-       { \
-         (a).size += (b).size; \
-         if ( ( ! (a).valid ) || ( (b).dmax > (a).dmax ) ) \
-           { \
-             (a).dmax = (b).dmax; \
-             (a).nsec = (b).nsec; \
-             (a).valid = 1; \
-           } \
-         else if ( ( (b).dmax == (a).dmax ) && ( (b).nsec > (a).nsec ) ) \
-           { \
-             (a).nsec = (b).nsec; \
-           } \
-       } \
-   } while (0)
+/* Initialize directory data.  */
+static inline void
+duinfo_init (struct duinfo *a)
+{
+  a->size = 0;
+  a->dmax = TYPE_MINIMUM (time_t);
+  a->nsec = -1;
+}
+
+/* Set directory data.  */
+static inline void
+duinfo_set (struct duinfo *a, uintmax_t size, time_t dmax, int nsec)
+{
+  a->size = size;
+  a->dmax = dmax;
+  a->nsec = nsec;
+}
+
+/* Accumulate directory data.  */
+static inline void
+duinfo_add (struct duinfo *a, struct duinfo const *b)
+{
+  a->size += b->size;
+  if (a->dmax < b->dmax
+      || (a->dmax == b->dmax && a->nsec < b->nsec))
+    {
+      a->dmax = b->dmax;
+      a->nsec = b->nsec;
+    }
+}
 
-/* A structure for per-directory level information */
+/* A structure for per-directory level information.  */
 struct dulevel
 {
-  struct duinfo  ent;         /* Entries in this directory */
-  struct duinfo  subdir;      /* Total for subdirectories */
+  /* Entries in this directory.  */
+  struct duinfo ent;
+
+  /* Total for subdirectories.  */
+  struct duinfo subdir;
 };
 
 /* Name under which this program was invoked.  */
@@ -150,14 +160,14 @@ static size_t max_depth = SIZE_MAX;
 /* Human-readable options for output.  */
 static int human_output_opts;
 
-/* If option non-zero, print most recently modified date, using the specified 
format */
-static int opt_last_time = 0;
+/* If true, print most recently modified date, using the specified format.  */
+static bool opt_time = false;
 
-/* Type of time to display. controlled by --last-time */
+/* Type of time to display. controlled by --time.  */
 
 enum time_type
   {
-    time_mtime,                        /* default */
+    time_mtime,                        /* default */
     time_ctime,
     time_atime
   };
@@ -177,7 +187,7 @@ static uintmax_t output_block_size;
 static struct exclude *exclude;
 
 /* Grand total size of all args, in bytes. Also latest modified date. */
-static struct duinfo tot_dui = { 0, 0, 0, 0 };
+static struct duinfo tot_dui = { 0, 0 };
 
 #define IS_DIR_TYPE(Type)      \
   ((Type) == FTS_DP            \
@@ -192,7 +202,7 @@ enum
   FILES0_FROM_OPTION,
   HUMAN_SI_OPTION,
   MAX_DEPTH_OPTION,
-  LAST_TIME_OPTION,
+  TIME_OPTION,
   TIME_STYLE_OPTION
 };
 
@@ -219,7 +229,7 @@ static struct option const long_options[
   {"separate-dirs", no_argument, NULL, 'S'},
   {"summarize", no_argument, NULL, 's'},
   {"total", no_argument, NULL, 'c'},
-  {"last-time", optional_argument, NULL, LAST_TIME_OPTION},
+  {"time", optional_argument, NULL, TIME_OPTION},
   {"time-style", required_argument, NULL, TIME_STYLE_OPTION},
   {GETOPT_HELP_OPTION_DECL},
   {GETOPT_VERSION_OPTION_DECL},
@@ -238,28 +248,24 @@ static enum time_type const time_types[]
 
 /* `full-iso' uses full ISO-style dates and times.  `long-iso' uses longer
    ISO-style time stamps, though shorter than `full-iso'.  `iso' uses shorter
-   ISO-style time stamps.  `locale' uses locale-dependent time stamps.  */
+   ISO-style time stamps.  */
 enum time_style
   {
     full_iso_time_style,       /* --time-style=full-iso */
     long_iso_time_style,       /* --time-style=long-iso */
-    iso_time_style,            /* --time-style=iso */
-    locale_time_style          /* --time-style=locale */
+    iso_time_style            /* --time-style=iso */
   };
 
 static char const *const time_style_args[] =
 {
-  "full-iso", "long-iso", "iso", "locale", 0
+  "full-iso", "long-iso", "iso", NULL
 };
 
 static enum time_style const time_style_types[] =
 {
-  full_iso_time_style, long_iso_time_style, iso_time_style,
-  locale_time_style, 0
+  full_iso_time_style, long_iso_time_style, iso_time_style, 0
 };
 
-static char const posix_prefix[] = "posix-";
-
 void
 usage (int status)
 {
@@ -317,14 +323,13 @@ Mandatory arguments to long options are 
                           --summarize\n\
 "), stdout);
       fputs (_("\
-      --last-time       show time of the most recent modification of any\n\
-                          file in the directory, or any of its 
subdirectories\n\
-      --last-time=WORD  show time as WORD instead of modification time:\n\
-                          atime, access, use, ctime or status; use\n\
+      --time            show time of the last modification of any file in 
the\n\
+                          directory, or any of its subdirectories\n\
+      --time=WORD       show time as WORD instead of modification time:\n\
+                          atime, access, use, ctime or status\n\
       --time-style=STYLE show times using style STYLE:\n\
-                          full-iso, long-iso, iso, locale, +FORMAT\n\
-                          FORMAT is interpreted like `date';\n\
-                          implies --last-time\n\
+                          full-iso, long-iso, iso, +FORMAT\n\
+                          FORMAT is interpreted like `date'\n\
 "), stdout);
       fputs (HELP_OPTION_DESCRIPTION, stdout);
       fputs (VERSION_OPTION_DESCRIPTION, stdout);
@@ -404,18 +409,13 @@ hash_init (void)
    in TIME_FORMAT.  If TIME_FORMAT is NULL, use the standard output format.
    Return zero if successful.  */
 
-static int
+static void
 show_date (const char *format, time_t when, int nsec)
 {
   struct tm *tm;
   char *out = NULL;
   size_t out_length = 0;
 
-  if (format == NULL || *format == '\0')
-    {
-      format = "%Y-%m-%d %H:%M";
-    }
-
   tm = localtime (&when);
   if (! tm)
     {
@@ -425,12 +425,11 @@ show_date (const char *format, time_t wh
              ? imaxtostr (when, buf)
              : umaxtostr (when, buf)));
       fputs (buf, stdout);
-      return 1;
+      return;
     }
 
-  while (1)
+  do
     {
-      bool done;
       out = x2nrealloc (out, &out_length, sizeof *out);
 
       /* Mark the first byte of the buffer so we can detect the case
@@ -438,17 +437,11 @@ show_date (const char *format, time_t wh
          would not terminate when date was invoked like this
          `LANG=de date +%p' on a system with good language support.  */
       out[0] = '\1';
-
-      done = (nstrftime (out, out_length, format, tm, 0, nsec)
-             || out[0] == '\0');
-
-      if (done)
-       break;
     }
+  while (nstrftime (out, out_length, format, tm, 0, nsec) == 0 && out[0]);
 
   fputs (out, stdout);
   free (out);
-  return 0;
 }
 
 /* Print N_BYTES.  Convert it to a readable value before printing.  */
@@ -461,15 +454,13 @@ print_only_size (uintmax_t n_bytes)
                         1, output_block_size), stdout);
 }
 
-/* Print N_BYTES followed by STRING on a line.
-   Optionally include last modified date.
-   Convert N_BYTES to a readable value before printing.  */
+/* Print size (and optionally time) indicated by *PDUI, followed by STRING.  */
 
 static void
 print_size (const struct duinfo *pdui, const char *string)
 {
   print_only_size (pdui->size);
-  if (opt_last_time)
+  if (opt_time)
     {
       putchar ('\t');
       show_date (time_format, pdui->dmax, pdui->nsec);
@@ -552,21 +543,21 @@ process_file (FTS *fts, FTSENT *ent)
       /* Note that we must not simply return here.
         We still have to update prev_level and maybe propagate
         some sums up the hierarchy.  */
-      DUINFO_INI (dui);
+      duinfo_init (&dui);
       print = false;
     }
   else
     {
-      DUINFO_SET (dui,
+      duinfo_set (&dui,
                  (apparent_size
                   ? sb->st_size
                   : ST_NBLOCKS (*sb) * ST_NBLOCKSIZE),
-                 ( time_type == time_ctime ) ? sb->st_ctime :
-                 ( time_type == time_atime ) ? sb->st_atime :
-                                               sb->st_mtime,
-                 ( time_type == time_ctime ) ? TIMESPEC_NS (sb->st_ctim) :
-                 ( time_type == time_atime ) ? TIMESPEC_NS (sb->st_atim) :
-                                               TIMESPEC_NS (sb->st_mtim));
+                 (time_type == time_ctime ? sb->st_ctime
+                  : time_type == time_atime ? sb->st_atime
+                  : sb->st_mtime),
+                 (time_type == time_ctime ? TIMESPEC_NS (sb->st_ctim)
+                  : time_type == time_atime ? TIMESPEC_NS (sb->st_atim)
+                  : TIMESPEC_NS (sb->st_mtim)));
     }
 
   level = ent->fts_level;
@@ -599,8 +590,8 @@ process_file (FTS *fts, FTSENT *ent)
 
          for (i = prev_level + 1; i <= level; i++)
            {
-             DUINFO_INI (dulvl[i].ent);
-             DUINFO_INI (dulvl[i].subdir);
+             duinfo_init (&dulvl[i].ent);
+             duinfo_init (&dulvl[i].subdir);
            }
        }
       else /* level < prev_level */
@@ -612,11 +603,11 @@ process_file (FTS *fts, FTSENT *ent)
             Here, the current level is always one smaller than the
             previous one.  */
          assert (level == prev_level - 1);
-         DUINFO_ADD (dui_to_print, dulvl[prev_level].ent);
+         duinfo_add (&dui_to_print, &dulvl[prev_level].ent);
          if (!opt_separate_dirs)
-           DUINFO_ADD (dui_to_print, dulvl[prev_level].subdir);
-         DUINFO_ADD (dulvl[level].subdir, dulvl[prev_level].ent);
-         DUINFO_ADD (dulvl[level].subdir, dulvl[prev_level].subdir);
+           duinfo_add (&dui_to_print, &dulvl[prev_level].subdir);
+         duinfo_add (&dulvl[level].subdir, &dulvl[prev_level].ent);
+         duinfo_add (&dulvl[level].subdir, &dulvl[prev_level].subdir);
        }
     }
 
@@ -625,11 +616,11 @@ process_file (FTS *fts, FTSENT *ent)
   /* Let the size of a directory entry contribute to the total for the
      containing directory, unless --separate-dirs (-S) is specified.  */
   if ( ! (opt_separate_dirs && IS_DIR_TYPE (ent->fts_info)))
-    DUINFO_ADD (dulvl[level].ent, dui);
+    duinfo_add (&dulvl[level].ent, &dui);
 
   /* Even if this directory is unreadable or we can't chdir into it,
      do let its size contribute to the total, ... */
-  DUINFO_ADD (tot_dui, dui);
+  duinfo_add (&tot_dui, &dui);
 
   /* ... but don't print out a total for it, since without the size(s)
      of any potential entries, it could be very misleading.  */
@@ -644,9 +635,7 @@ process_file (FTS *fts, FTSENT *ent)
 
   if ((IS_DIR_TYPE (ent->fts_info) && level <= max_depth)
       || ((opt_all && level <= max_depth) || level == 0))
-    {
-      print_size (&dui_to_print, file);
-    }
+    print_size (&dui_to_print, file);
 
   return ok;
 }
@@ -854,14 +843,15 @@ main (int argc, char **argv)
          add_exclude (exclude, optarg, EXCLUDE_WILDCARDS);
          break;
 
-       case LAST_TIME_OPTION:
-         opt_last_time = 1;
-         if ( optarg )
-           time_type = XARGMATCH ("--last-time", optarg, time_args, 
time_types);
+       case TIME_OPTION:
+         opt_time = true;
+         time_type =
+           (optarg
+            ? XARGMATCH ("--time", optarg, time_args, time_types)
+            : time_mtime);
          break;
 
        case TIME_STYLE_OPTION:
-         opt_last_time = 1;
          time_style = optarg;
          break;
 
@@ -899,22 +889,36 @@ main (int argc, char **argv)
   if (opt_summarize_only)
     max_depth = 0;
 
-  /* Process time style if printing last times */
-  if ( opt_last_time )
+  /* Process time style if printing last times.  */
+  if (opt_time)
     {
-      if (! time_style )
-       if (! (time_style = getenv ("TIME_STYLE")))
-         time_style = "posix-long-iso";
+      if (! time_style)
+       {
+         time_style = getenv ("TIME_STYLE");
 
-      while (strncmp (time_style, posix_prefix, sizeof posix_prefix - 1) == 0)
-        {
-          time_style += sizeof posix_prefix - 1;
-        }
+         /* Ignore TIMESTYLE="locale", for compatibility with ls.  */
+         if (! time_style || STREQ (time_style, "locale"))
+           time_style = "long-iso";
+         else if (*time_style == '+')
+           {
+             /* Ignore anything after a newline, for compatibility
+                with ls.  */
+             char *p = strchr (time_style, '\n');
+             if (p)
+               *p = '\0';
+           }
+         else
+           {
+             /* Ignore "posix-" prefix, for compatibility with ls.  */
+             static char const posix_prefix[] = "posix-";
+             while (strncmp (time_style, posix_prefix, sizeof posix_prefix - 1)
+                    == 0)
+               time_style += sizeof posix_prefix - 1;
+           }
+       }
 
       if (*time_style == '+')
-        {
-          time_format = time_style + 1;
-        }
+       time_format = time_style + 1;
       else
         {
           switch (XARGMATCH ("time style", time_style,
@@ -929,12 +933,8 @@ main (int argc, char **argv)
              break;
 
            case iso_time_style:
-             time_format = "%Y-%m-%d ";
+             time_format = "%Y-%m-%d";
              break;
-
-           case locale_time_style:
-             if (hard_locale (LC_TIME))
-               time_format = dcgettext (NULL, time_format, LC_TIME);
             }
         }
     }