Add support for $kak_command_fifo and $kak_response_fifo

Those fifos are accessible during %sh{...} blocks, the command fifo
executes commands written to it once the write end side is closed
(multiple open/write/close sequences are supported), the response
fifo is a simple helper fifo available to write response back to
the shell process

An example use of this feature is to request some list options
content from without being limited by the environment size:
```
%sh{
    echo "echo -to-file $kak_response_fifo -quoting shell -- %opt{some_list}" > $kak_command_fifo
    eval "set -- $(cat $kak_response_fifo)"
}
```
This commit is contained in:
Maxime Coste 2021-06-15 21:38:17 +10:00
parent 6215bff764
commit 3d7fb8ddbc
3 changed files with 74 additions and 8 deletions

View File

@ -166,6 +166,24 @@ TIP: These environment variables are also available in other contexts where
Kakoune uses a shell command, such as the `|`, `!` or `$` normal mode commands Kakoune uses a shell command, such as the `|`, `!` or `$` normal mode commands
(See <<keys#,`:doc keys`>>). (See <<keys#,`:doc keys`>>).
=== Command and Response fifo
Inside shell expansions, `$kak_command_fifo` refers to a named pipe that
accepts Kakoune commands to be executed as soon as the fifo is closed. This
named pipe can be opened and closed multiple times which makes it possible
to interleave shell and Kakoune commands. `$kak_response_fifo` refers to
a named pipe that can be used to return data from Kakoune.
---
%sh{
echo "write $kak_response_fifo" > $kak_command_fifo
content="$(cat $kak_response_fifo)"
}
---
This also makes it possible to pass data bigger than the system environment
size limit.
== File expansions == File expansions
Expansions with the type `file` will expand to the content of the filename Expansions with the type `file` will expand to the content of the filename

View File

@ -46,6 +46,7 @@ public:
void run(FdEvents events, EventMode mode); void run(FdEvents events, EventMode mode);
void reset_fd(int fd) { m_fd = fd; }
void close_fd(); void close_fd();
void disable() { m_fd = -1; } void disable() { m_fd = -1; }

View File

@ -4,6 +4,7 @@
#include "client.hh" #include "client.hh"
#include "clock.hh" #include "clock.hh"
#include "context.hh" #include "context.hh"
#include "command_manager.hh"
#include "display_buffer.hh" #include "display_buffer.hh"
#include "event_manager.hh" #include "event_manager.hh"
#include "face_registry.hh" #include "face_registry.hh"
@ -163,18 +164,19 @@ Vector<String> generate_env(StringView cmdline, const Context& context, GetValue
return env; return env;
} }
FDWatcher make_pipe_reader(Pipe& pipe, String& contents) template<typename OnClose>
FDWatcher make_reader(int fd, String& contents, OnClose&& on_close)
{ {
return {pipe.read_fd(), FdEvents::Read, EventMode::Urgent, return {fd, FdEvents::Read, EventMode::Urgent,
[&contents, &pipe](FDWatcher& watcher, FdEvents, EventMode) { [fd, &contents, on_close](FDWatcher& watcher, FdEvents, EventMode) {
char buffer[1024]; char buffer[1024];
while (fd_readable(pipe.read_fd())) while (fd_readable(fd))
{ {
size_t size = ::read(pipe.read_fd(), buffer, sizeof(buffer)); size_t size = ::read(fd, buffer, sizeof(buffer));
if (size <= 0) if (size <= 0)
{ {
pipe.close_read_fd();
watcher.disable(); watcher.disable();
on_close();
return; return;
} }
contents += StringView{buffer, buffer+size}; contents += StringView{buffer, buffer+size};
@ -206,6 +208,41 @@ FDWatcher make_pipe_writer(Pipe& pipe, StringView contents)
}}; }};
} }
struct CommandFifos
{
String base_dir;
String command;
FDWatcher command_watcher;
CommandFifos(Context& context, const ShellContext& shell_context)
: base_dir(format("{}/kak-fifo.XXXXXX", tmpdir())),
command_watcher([&] {
mkdtemp(base_dir.data()),
mkfifo(command_fifo_path().c_str(), 0600);
mkfifo(response_fifo_path().c_str(), 0600);
int fd = open(command_fifo_path().c_str(), O_RDONLY | O_NONBLOCK);
return make_reader(fd, command, [&, fd] {
close(fd);
CommandManager::instance().execute(command, context, shell_context);
command.clear();
command_watcher.reset_fd(open(command_fifo_path().c_str(), O_RDONLY | O_NONBLOCK));
});
}())
{
}
~CommandFifos()
{
command_watcher.close_fd();
unlink(command_fifo_path().c_str());
unlink(response_fifo_path().c_str());
rmdir(base_dir.c_str());
}
String command_fifo_path() const { return format("{}/command-fifo", base_dir); }
String response_fifo_path() const { return format("{}/response-fifo", base_dir); }
};
} }
std::pair<String, int> ShellManager::eval( std::pair<String, int> ShellManager::eval(
@ -219,7 +256,17 @@ std::pair<String, int> ShellManager::eval(
auto start_time = profile ? Clock::now() : Clock::time_point{}; auto start_time = profile ? Clock::now() : Clock::time_point{};
Optional<CommandFifos> command_fifos;
auto kak_env = generate_env(cmdline, context, [&](StringView name, Quoting quoting) { auto kak_env = generate_env(cmdline, context, [&](StringView name, Quoting quoting) {
if (name == "command_fifo" or name == "response_fifo")
{
if (not command_fifos)
command_fifos.emplace(const_cast<Context&>(context), shell_context);
return name == "command_fifo" ?
command_fifos->command_fifo_path() : command_fifos->response_fifo_path();
}
if (auto it = shell_context.env_vars.find(name); it != shell_context.env_vars.end()) if (auto it = shell_context.env_vars.find(name); it != shell_context.env_vars.end())
return it->value; return it->value;
return join(get_val(name, context) | transform(quoter(quoting)), ' ', false); return join(get_val(name, context) | transform(quoter(quoting)), ' ', false);
@ -259,8 +306,8 @@ std::pair<String, int> ShellManager::eval(
auto wait_time = Clock::now(); auto wait_time = Clock::now();
String stdout_contents, stderr_contents; String stdout_contents, stderr_contents;
auto stdout_reader = make_pipe_reader(child_stdout, stdout_contents); auto stdout_reader = make_reader(child_stdout.read_fd(), stdout_contents, [&]{ child_stdout.close_read_fd(); });
auto stderr_reader = make_pipe_reader(child_stderr, stderr_contents); auto stderr_reader = make_reader(child_stderr.read_fd(), stderr_contents, [&]{ child_stderr.close_read_fd(); });
auto stdin_writer = make_pipe_writer(child_stdin, input); auto stdin_writer = make_pipe_writer(child_stdin, input);
// block SIGCHLD to make sure we wont receive it before // block SIGCHLD to make sure we wont receive it before