revamp all tools help messages

The general idea is: A small paragraph on the tool itself as a
description, a list of the most used (!= all) commands available in the
tool, a remark where to find more information on the tool and its
commands (aka: in the manpage) and finally a common block referring to
even more manpages. In exchange options are completely omitted from the
output as well as deprecated or obscure commands. (Better) Information
about them is available in the manpages anyway and the few options which
were listed before were also the least interesting ones (-o -c -q and co
are hardly of interest for someone totally new looking to find info by
asking for help and anyone with a bit of experience doesn't need this
short list. Those would need a list of options applying to the command
they call, but they are too numerous and command specific to list them
sanely in this context.

1 files changed, 7 insertions, 15 deletions

diff --git a/cmdline/apt-cache.cc b/cmdline/apt-cache.cc
index 465911570..dd1488568 100644
--- a/cmdline/apt-cache.cc
+++ b/cmdline/apt-cache.cc
@@ -1202,26 +1202,18 @@ static bool GenCaches(CommandLine &)
    return CacheFile.BuildCaches(&Progress, true);
 }
 									/*}}}*/
-bool ShowHelp(CommandLine &, aptDispatchWithHelp const * Cmds)		/*{{{*/
+bool ShowHelp(CommandLine &)						/*{{{*/
 {
    std::cout <<
     _("Usage: apt-cache [options] command\n"
       "       apt-cache [options] show pkg1 [pkg2 ...]\n"
       "\n"
-      "apt-cache is a low-level tool used to query information\n"
-      "from APT's binary cache files\n")
-    << std::endl;
-   ShowHelpListCommands(Cmds);
-   std::cout << std::endl
-    << _("Options:\n"
-      "  -h   This help text.\n"
-      "  -p=? The package cache.\n"
-      "  -s=? The source cache.\n"
-      "  -q   Disable progress indicator.\n"
-      "  -i   Show only important deps for the unmet command.\n"
-      "  -c=? Read this configuration file\n"
-      "  -o=? Set an arbitrary configuration option, eg -o dir::cache=/tmp\n"
-      "See the apt-cache(8) and apt.conf(5) manual pages for more information.\n");
+      "apt-cache queries and displays available information about installed\n"
+      "as well as installable packages. It works exclusively on the data\n"
+      "acquired via the 'update' command of e.g. apt-get to the local cache.\n"
+      "The displayed information can therefore be outdated if the last update\n"
+      "is too long ago, but in exchange apt-cache works independently of the\n"
+      "availability of the configured sources (e.g. offline).\n");
    return true;
 }
 									/*}}}*/