doc: clarify --help output for some optional arguments

* src/pr.c (usage): Fix the -S description to indicate
that the argument is optional for the short option.
* doc/coreutils.texi (pr invocation): Likewise.
* src/od.c (usage): Fix the -S description to indicate
that the argument is required for the short option.
Clarify -w takes an argument and that it is optional.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/od.c b/src/od.c
index 2da282511..759379692 100644
--- a/src/od.c
+++ b/src/od.c
@@ -313,10 +313,10 @@ All arguments to long options are mandatory for short options.\n\
 "), stdout);
       fputs (_("\
   -N, --read-bytes=BYTES      limit dump to BYTES input bytes\n\
-  -S, --strings[=BYTES]       output strings of at least BYTES graphic chars\n\
+  -S BYTES, --strings[=BYTES]  output strings of at least BYTES graphic chars\n\
   -t, --format=TYPE           select output format or formats\n\
   -v, --output-duplicates     do not use * to mark line suppression\n\
-  -w, --width[=BYTES]         output BYTES bytes per output line\n\
+  -w[BYTES], --width[=BYTES]  output BYTES bytes per output line\n\
       --traditional           accept arguments in traditional form\n\
 "), stdout);
       fputs (HELP_OPTION_DESCRIPTION, stdout);