diff options
| -rwxr-xr-x | lclipd.lua | 50 |
1 files changed, 34 insertions, 16 deletions
@@ -27,6 +27,8 @@ local function default_luarocks_modules() end default_luarocks_modules() +-- we want to delete a pidfile if we wrote one +local wrote_a_pidfile = false local signal = require("posix.signal") local argparse = require("argparse") local sys_stat = require("posix.sys.stat") @@ -85,7 +87,7 @@ local db_file_name = "/tmp/lclipd_db_name" local function sleep(n) os.execute("sleep " .. tonumber(n)) end --- We are not longer running. -local function remove_pid_file() os.remove(pid_file) end +local function remove_pid_file() if wrote_a_pidfile then os.remove(pid_file) end end --- Adds LUA_PATH and LUA_CPATH to the current interpreters path. @@ -113,16 +115,32 @@ local function check_uid_gid() posix_syslog.LOG_INFO) end ---- Checks to make sure that the pid file for clipd does not exist. +--- Tries to determine whether another instance is running, if yes, quits local function check_pid_file() local f = sys_stat.stat(pid_file) if f ~= nil then - log_to_syslog("clipd is already running", posix_syslog.LOG_CRIT) - lclip_exit(1) + local pid_file_handle = io.open(pid_file, "r") + local pid_file_content = pid_file_handle:read("*a") + pid_file_content = pid_file_content:gsub("\n", "") + log_to_syslog(pid_file_content, posix_syslog.LOG_INFO) + + local old_pid_file = sys_stat.stat("/proc/" .. pid_file_content) + if old_pid_file ~= nil then + local pid_cmdline = io.open("/proc/" .. pid_file_content .. + "/cmdline", "r") + local pid_cmdline_content = pid_cmdline:read("*a") + if string.match(pid_cmdline_content, "lclipd") then + -- we assume a lclipd instance is already running at this point + log_to_syslog("clipd is already running", posix_syslog.LOG_CRIT) + lclip_exit(1) + end + -- the old pid file is stale, meaning the previous instance + -- died without being able to clean up after itself + end end end ---- instance running. +--- Write a pidfile local function write_pid_file() local f = io.open(pid_file, "w") if f == nil then @@ -130,28 +148,28 @@ local function write_pid_file() lclip_exit(1) end f:write(tostring(unistd.getpid())) + wrote_a_pidfile = true end --- Get the clipboard content from X or wayland. local function get_clipboard_content() - -- if we use a plain os.execute for clipnotify we wont get the ctrl-c - -- when it is pressed. doing it manually though the parent receives + -- if we use a plain os.execute for clipnotify the parent wont get the + -- SIGINT when it is passed. if we fork though, the parent receives -- the SIGINT just fine. local pid, errmsg = unistd.fork() - if pid == nil then + if pid == nil then -- error log_to_syslog("could not fork", posix_syslog.LOG_CRIT) log_to_syslog(errmsg, posix_syslog.LOG_CRIT) - remove_pid_file() - os.exit(1) - elseif pid == 0 then + lclip_exit(1) + elseif pid == 0 then -- child -- clipnotify exits when there is a new entry on the clipboard -- so we do want a blocking call here os.execute("clipnotify") os.exit(0) - else + else -- parent posix_wait.wait(pid) - -- we dont care whether all the calls to clipboard progs succeed - -- or not. so we just mask the errors. + -- we dont care whether all the calls to the different clipboard apps + -- succeed or not so we just ignore the errors. local _, handle_x = pcall(io.popen, "xsel -ob") local last_clip_entry_x = handle_x:read("*a") @@ -261,8 +279,8 @@ local function main() end) local args = parser:parse() - -- check_pid_file() - -- write_pid_file() + check_pid_file() + write_pid_file() check_uid_gid() local status, err = pcall(loop, args["hist_size"]) if status ~= true then log_to_syslog(err, posix_syslog.LOG_CRIT) end |