doc: Improve description of --files0-from option

* doc/coreutils.texi: Describe the most common
usage of --files0-from=- to read names from stdin.
* src/du.c: Likewise.
* src/sort.c: Likewise.
* src/wc.c: Likewise.

4 files changed, 11 insertions, 7 deletions

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index cf56cadb2..0e2f1500e 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -3266,17 +3266,18 @@ Print only the maximum line lengths.
 @c This is commented out to avoid a texi2dvi failure.
 @c texi2dvi (GNU Texinfo 4.11) 1.104
 @c @cindex including files from @command{\cmd\}
-Rather than processing files named on the command line, process those
-named in file @var{FILE}; each name is terminated by a null byte.
+Disallow processing files named on the command line, and instead process
+those named in file @var{FILE}; each name being terminated by a NUL byte.
 This is useful \withTotalOption\
 when the list of file names is so long that it may exceed a command line
 length limitation.
 In such cases, running @command{\cmd\} via @command{xargs} is undesirable
 because it splits the list into pieces and makes @command{\cmd\} print
 \subListOutput\ for each sublist rather than for the entire list.
-One way to produce a list of null-byte-terminated file names is with @sc{gnu}
+One way to produce a list of NUL terminated file names is with @sc{gnu}
 @command{find}, using its @option{-print0} predicate.
-Do not specify any @var{FILE} on the command line when using this option.
+If @var{FILE} is @samp{-} then the NUL terminated file names
+are read from standard input.
 @end macro
 @filesZeroFromOption{wc,,a total}
 
diff --git a/src/du.c b/src/du.c
index 2b0792b37..e5669786d 100644
--- a/src/du.c
+++ b/src/du.c
@@ -292,7 +292,8 @@ Mandatory arguments to long options are mandatory for short options too.\n\
 "), stdout);
       fputs (_("\
       --files0-from=F   summarize disk usage of the NUL-terminated file\n\
-                          names specified in file F\n\
+                          names specified in file F;\n\
+                          If F is - then read names from standard input\n\
   -H                    like --si, but also evokes a warning; will soon\n\
                           change to be equivalent to --dereference-args (-D)\n\
   -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)\n\
diff --git a/src/sort.c b/src/sort.c
index df51d8b33..f43856315 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -363,7 +363,8 @@ Other options:\n\
       --compress-program=PROG  compress temporaries with PROG;\n\
                               decompress them with PROG -d\n\
       --files0-from=F       read input from the files specified by\n\
-                            NUL-terminated names in file F\n\
+                            NUL-terminated names in file F;\n\
+                            If F is - then read names from standard input\n\
 "), stdout);
       fputs (_("\
   -k, --key=POS1[,POS2]     start a key at POS1 (origin 1), end it at POS2\n\
diff --git a/src/wc.c b/src/wc.c
index 280d7ac88..8cfd974ca 100644
--- a/src/wc.c
+++ b/src/wc.c
@@ -121,7 +121,8 @@ read standard input.\n\
 "), stdout);
       fputs (_("\
       --files0-from=F    read input from the files specified by\n\
-                           NUL-terminated names in file F\n\
+                           NUL-terminated names in file F;\n\
+                           If F is - then read names from standard input\n\
   -L, --max-line-length  print the length of the longest line\n\
   -w, --words            print the word counts\n\
 "), stdout);