commands: harmonize in-barebox documentation

This patch does probably too much, but it's hard (and very
cumbersome/time consuming) to break it out. What is does is this:

* each command has one short description, e.g. "list MUX configuration"
* made sure the short descriptions start lowercase
* each command has one usage. That string contains just the
  options, e.g. "[-npn]". It's not part of the long help text.
* that is, it doesn't say "[OPTIONS]" anymore, every usable option
  is listed by character in this (short) option string (the long
  description is in the long help text, as before)
* help texts have been reworked, to make them
  - sometimes smaller
  - sometimes describe the options better
  - more often present themselves in a nicer format
* all long help texts are now created with BUSYBOX_CMD_HELP_
  macros, no more 'static const __maybe_unused char cmd_foobar_help[]'
* made sure the long help texts starts uppercase
* because cmdtp->name and cmdtp->opts together provide the new usage,
  all "Usage: foobar" texts have been removed from the long help texts
* BUSYBOX_CMD_HELP_TEXT() provides the trailing newline by itself, this
  is nicer in the source code
* BUSYBOX_CMD_HELP_OPT() provides the trailing newline by itself
* made sure no line gets longer than 77 characters
* delibertely renamed cmdtp->usage, so that we can get compile-time
  errors (e.g. in out-of-tree modules that use register_command()
* the 'help' command can now always emit the usage, even without
  compiled long help texts
* 'help -v' gives a list of commands with their short description, this
  is similar like the old "help" command before my patchset
* 'help -a' gives out help of all commands

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 2 insertions, 5 deletions

diff --git a/net/dns.c b/net/dns.c
index 847458b8af..4506bafab6 100644
--- a/net/dns.c
+++ b/net/dns.c
@@ -260,13 +260,10 @@ static int do_host(int argc, char *argv[])
 	return 0;
 }
 
-static const __maybe_unused char cmd_host_help[] =
-"Usage: host <hostname>\n";
-
 BAREBOX_CMD_START(host)
 	.cmd		= do_host,
-	.usage		= "resolve a hostname",
+	BAREBOX_CMD_DESC("resolve a hostname")
+	BAREBOX_CMD_OPTS("HOSTNAME")
 	BAREBOX_CMD_GROUP(CMD_GRP_NET)
-	BAREBOX_CMD_HELP(cmd_host_help)
 BAREBOX_CMD_END