kdb-ls-depth: Implement depth parameter for kdb ls

doc/help/kdb-ls.md

@@ -19,21 +19,76 @@ This command will list the name of all keys below a given path.
   Print version info.
 - `-p`, `--profile`=<profile>:
   Use a different kdb profile.
+- `-m`, `--min-depth`=<min-depth>:
+  Specify the minimum path depth of the output (0 by default), exclusive 
+  and relative to the name to list.
+- `-M`, `--max-depth`=<max-depth>:
+  Specify the maximum path depth of the output (unlimited by default, 1 
+  to show only the next level), inclusive and relative to the name to list.
 - `-v`, `--verbose`:
   Explain what is happening.
 - `-0`, `--null`:
   Use binary 0 termination.
 - `-C`, `--color`=[when]:
   Print never/auto(default)/always colored output.
+- `-d`, `--debug`:
+  Give debug information.
 
 ## EXAMPLES
 
-To list all keys below `user/example`:  
-`kdb ls user/example`  
+```sh
 
+# Create the keys we use for the examples
+kdb set /sw/elektra/examples/kdb-ls/test val1
+kdb set /sw/elektra/examples/kdb-ls/test/foo/bar val2
+kdb set /sw/elektra/examples/kdb-ls/test/fizz/buzz fizzbuzz
+kdb set /sw/elektra/examples/kdb-ls/tost val3
+kdb set /sw/elektra/examples/kdb-ls/tost/level lvl 
+
+# list all keys below /sw/elektra/examples/kdb-ls
+kdb ls /sw/elektra/examples/kdb-ls
+#>user/sw/elektra/examples/kdb-ls/test
+#>user/sw/elektra/examples/kdb-ls/test/fizz/buzz
+#>user/sw/elektra/examples/kdb-ls/test/foo/bar
+#>user/sw/elektra/examples/kdb-ls/tost
+#>user/sw/elektra/examples/kdb-ls/tost/level
+
+# list the next level of keys below /sw/elektra/examples/kdb-ls
+# note that if the search key ends with a /, it lists the next level
+kdb ls /sw/elektra/examples/kdb-ls/ --max-depth=1
+#>user/sw/elektra/examples/kdb-ls/test
+#>user/sw/elektra/examples/kdb-ls/tost
+
+# list the current level of keys below /sw/elektra/examples/kdb-ls
+# note the difference to the previous example
+kdb ls /sw/elektra/examples/kdb-ls --max-depth=1
+# this yields no output as /sw/elektra/examples/kdb-ls is not a key
+
+# list all keys below /sw/elektra/examples/kdb-ls with are minimum 1 level away from that key
+# and maximum 2 levels away
+kdb ls /sw/elektra/examples/kdb-ls --min-depth=1 --max-depth=2
+#>user/sw/elektra/examples/kdb-ls/tost/level
+
+# list all keys below /sw/elektra/examples/kdb-ls/test
+kdb ls /sw/elektra/examples/kdb-ls/test
+#>user/sw/elektra/examples/kdb-ls/test
+#>user/sw/elektra/examples/kdb-ls/test/fizz/buzz
+#>user/sw/elektra/examples/kdb-ls/test/foo/bar
+
+# list all keys under /sw/elektra/examples/kdb-ls in verbose mode
+kdb ls /sw/elektra/examples/kdb-ls/ -v
+#>size of all keys in mountpoint: 31
+#>size of requested keys: 5
+#>user/sw/elektra/examples/kdb-ls/test
+#>user/sw/elektra/examples/kdb-ls/test/fizz/buzz
+#>user/sw/elektra/examples/kdb-ls/test/foo/bar
+#>user/sw/elektra/examples/kdb-ls/tost
+#>user/sw/elektra/examples/kdb-ls/tost/level
+
+```
 
 ## SEE ALSO
 
 - If the user would also like to see the values of the keys below `path` then you should
 consider the [kdb-export(1)](kdb-export.md) command.
-- [elektra-key-names(7)](elektra-key-names.md) for an explanation of key names.
+- [elektra-key-names(7)](elektra-key-names.md) for an explanation of key names.

src/tools/kdb/ls.cpp

@@ -23,10 +23,7 @@ LsCommand::LsCommand () : kdb (root)
 
 int LsCommand::execute (Cmdline const & cl)
 {
-	if (cl.arguments.size () != 1)
-	{
-		throw invalid_argument ("1 argument required");
-	}
+	checkArguments (cl);
 
 	printWarnings (cerr, root);
 
@@ -45,13 +42,71 @@ int LsCommand::execute (Cmdline const & cl)
 		cout.unsetf (std::ios_base::skipws);
 	}
 
-	cout << part;
+	printResults (part, getDepth (root), cl);
 
 	printWarnings (cerr, root);
 
 	return 0;
 }
 
+void LsCommand::checkArguments (Cmdline const & cl)
+{
+	if (cl.arguments.size () != 1)
+	{
+		throw invalid_argument ("1 argument required");
+	}
+	if (cl.maxDepth <= cl.minDepth)
+	{
+		throw invalid_argument ("the maximum depth has to be larger than the minimum depth");
+	}
+	if (cl.maxDepth < 0)
+	{
+		throw invalid_argument ("the maximum depth has to be a positive number");
+	}
+	if (cl.minDepth < 0)
+	{
+		throw invalid_argument ("the minimum depth has to be a positive number");
+	}
+}
+
+void LsCommand::printResults (KeySet const & part, const int rootDepth, Cmdline const & cl)
+{
+	const int offset = root.getBaseName ().empty () || shallShowNextLevel (cl.arguments[0]) ? 1 : 0;
+	const int relativeMinDepth = rootDepth + cl.minDepth + offset;
+	const int relativeMaxDepth = std::max (cl.maxDepth, rootDepth + cl.maxDepth + offset);
+	if (cl.debug)
+	{
+		cout << "The root depth is " << rootDepth << ", the relative minimum depth is " << relativeMinDepth
+		     << " and the relative maximum depth is " << relativeMaxDepth << endl;
+	}
+
+	for (const auto & it : part)
+	{
+		const int depth = getDepth (it);
+		if ((depth >= relativeMinDepth && depth < relativeMaxDepth) || cl.debug)
+		{
+			cout << it;
+			if (cl.debug)
+			{
+				cout << " " << depth;
+			}
+			cout << endl;
+		}
+	}
+}
+
+int LsCommand::getDepth (Key const & key)
+{
+	return std::distance (key.begin (), key.end ());
+}
+
+bool LsCommand::shallShowNextLevel (const string argument)
+{
+	auto it = argument.rbegin ();
+	// If the argument ends in / its an indicator to complete the next level (like done by shells), but not if its escaped
+	return it != argument.rend () && (*it) == '/' && ((++it) == argument.rend () || (*it) != '\\');
+}
+
 LsCommand::~LsCommand ()
 {
 }

src/tools/kdb/ls.hpp

@@ -25,7 +25,7 @@ class LsCommand : public Command
 
 	virtual std::string getShortOptions () override
 	{
-		return "v0C";
+		return "dM:m:v0C";
 	}
 
 	virtual std::string getSynopsis () override
@@ -46,6 +46,12 @@ class LsCommand : public Command
 	}
 
 	virtual int execute (Cmdline const & cmdline) override;
+
+private:
+	void checkArguments (Cmdline const & cl);
+	void printResults (kdb::KeySet const & part, const int rootDepth, Cmdline const & cl);
+	int getDepth (kdb::Key const & key);
+	bool shallShowNextLevel (const std::string argument);
 };
 
 #endif

tests/shell/shell_recorder/tutorial_wrapper/CMakeLists.txt

@@ -17,6 +17,7 @@ endfunction ()
 
 add_s_test (tutorial_cascading "${CMAKE_SOURCE_DIR}/doc/tutorials/cascading.md")
 add_s_test (kdb-complete "${CMAKE_SOURCE_DIR}/doc/help/kdb-complete.md")
+add_s_test (kdb-ls "${CMAKE_SOURCE_DIR}/doc/help/kdb-ls.md")
 add_s_test (kdb-global-umount "${CMAKE_SOURCE_DIR}/doc/help/kdb-global-umount.md")
 
 add_plugin_shell_test (blockresolver)