Re: Should "df --portability" allow thousands separators?

[Paul Eggert]

"Peter D." <address@hidden> writes:

> When an inconsistent set of environment variables and command 
> line options is given then sending a polite informative version 
> of "programming error" to standard error is useful.  However, 
> sending most sensible output to standard out will cause the 
> least grief.  

I also would prefer avoiding a diagnostic if possible.  Also, it
seems confusing to pay attention to part of an environment variable,
but ignore the rest.

How about using the following rule instead?

   If -P is used, ignore the DF_BLOCK_SIZE, BLOCK_SIZE, and BLOCKSIZE
   environment variables.

This is easier to document and understand (at least for me....).

Here's a proposed patch to do that.

A more-radical option would be to also ignore POSIXLY_CORRECT if -P is
specified: i.e., the default block size is 512 if -P is used.  This
would be more "in the spirit of POSIX" but would be less compatible
with existing GNU practice.

[ChangeLog]
* NEWS: With -P, the default block size and output format is not
affected by DF_BLOCK_SIZE, BLOCK_SIZE, or BLOCKSIZE.
* src/df.c (main): Implement this.
[doc/ChangeLog]
* coreutils.texi (df invocation): With -P, the default block size
and output format is not affected by DF_BLOCK_SIZE, BLOCK_SIZE, or
BLOCKSIZE.
diff --git a/NEWS b/NEWS
index 08724b7..65a7d52 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,11 @@ GNU coreutils NEWS                                    -*- 
outline -*-

 * Noteworthy changes in release 6.8+ (????-??-??) [not-unstable]

+** Bug fixes
+
+  The default block size and output format for df -P are now unaffected by
+  the DF_BLOCK_SIZE, BLOCK_SIZE, and BLOCKSIZE environment variables.  It
+  is still affected by POSIXLY_CORRECT, though.

 * Noteworthy changes in release 6.8 (2007-02-24) [not-unstable]

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 99412e4..b313afd 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -9481,6 +9481,13 @@ some network mounts), the columns are misaligned.

 @item
 The labels in the header output line are changed to conform to @acronym{POSIX}.
+
address@hidden
+The default block size and output format are unaffected by the
address@hidden, @env{BLOCK_SIZE} and @env{BLOCKSIZE} environment
+variables.  However, the default block size is still affected by
address@hidden: it is 512 if @env{POSIXLY_CORRECT} is set, 1024
+otherwise.  @xref{Block size}.
 @end enumerate

 @optSi
diff --git a/src/df.c b/src/df.c
index 8bc4a84..609787e 100644
--- a/src/df.c
+++ b/src/df.c
@@ -796,10 +796,7 @@ main (int argc, char **argv)
   inode_format = false;
   show_all_fs = false;
   show_listed_fs = false;
-
-  human_output_opts = human_options (getenv ("DF_BLOCK_SIZE"), false,
-                                    &output_block_size);
-
+  human_output_opts = -1;
   print_type = false;
   file_systems_processed = false;
   posix_format = false;
@@ -876,6 +873,18 @@ main (int argc, char **argv)
        }
     }

+  if (human_output_opts == -1)
+    {
+      if (posix_format)
+       {
+         human_output_opts = 0;
+         output_block_size = (getenv ("POSIXLY_CORRECT") ? 512 : 1024);
+       }
+      else
+       human_output_opts = human_options (getenv ("DF_BLOCK_SIZE"), false,
+                                          &output_block_size);
+    }
+
   /* Fail if the same file system type was both selected and excluded.  */
   {
     bool match = false;
M ChangeLog
M NEWS
M doc/ChangeLog
M doc/coreutils.texi
M src/df.c
Committed as 8593bc37abba49958a143aea2ed01bd9f01e7a2a