1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
-- Copyright (c) 2024 Florian Fischer. All rights reserved.
--
-- vis-lockfiles is free software: you can redistribute it and/or modify it under
-- the terms of the GNU General Public License as published by the Free Software
-- Foundation, either version 3 of the License, or (at your option) any later
-- version.
--
-- vis-lockfiles is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-- FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License along with
-- vis-lockfiles found in the LICENSE file.
-- If not, see <https://www.gnu.org/licenses/>.
local M = {}
M.directory = '${XDG_STATE_HOME:-${HOME}/.local/state}/vis/locks'
-- Helper to execute a command and capture its output
local function capture_cmd(cmd)
local p = assert(io.popen(cmd, 'r'))
local s = assert(p:read('*a'))
local success, _, status = p:close()
if not success then
local err = cmd .. ' failed with exit code: ' .. status
vis:info('vis-lockfiles: ' .. err)
end
return s
end
local function lock_file_path(path)
local filename = path:gsub('/', '%%')
assert(os.execute('mkdir -p "' .. M.directory .. '"'))
return capture_cmd('printf %s "' .. M.directory .. '/' .. filename .. '.lock"')
end
-- determine vis' pid
local vis_pid
do
local vis_proc_file = io.open('/proc/self/stat', 'r')
if vis_proc_file then
vis_pid = vis_proc_file:read('*n')
vis_proc_file:close()
else -- fallback if /proc/self/stat is not available
local out = capture_cmd('sh -c "echo $PPID"')
vis_pid = tonumber(out)
end
end
assert(vis_pid)
-- get a user confirmation
-- return true if user selected yes, false otherwise
local function confirm(path)
local choices = 'no\nyes'
local prompt = path .. ' exists. Edit anyway:'
local cmd = 'printf "' .. choices .. '" | vis-menu -b -p \'' .. prompt .. '\''
local choice = nil
-- local status, output = vis:pipe(nil, {start = 0, finish = 0}, cmd)
local menu = assert(io.popen(cmd))
local output = menu:read('*a')
local _, _, status = menu:close()
if status == 0 then
-- trim newline from selection
if output:sub(-1) == '\n' then
choice = output:sub(1, -2)
else
choice = output
end
end
vis:redraw()
return choice == 'yes'
end
local created_locks = {}
local function create_lock_file(lfile_path)
local lock_file = io.open(lfile_path)
if lock_file then
lock_file:close()
return false
end
-- create the lock file with our pid
lock_file = assert(io.open(lfile_path, 'w'))
lock_file:write(vis_pid)
lock_file:close()
-- detect a possible race
lock_file = assert(io.open(lfile_path))
local lock_pid = lock_file:read('*n')
lock_file:close()
local locked = tonumber(lock_pid) == vis_pid
-- remember we created the lock file
if locked then
created_locks[lfile_path] = true
end
return locked
end
local function delete_lock_file(lfile_path)
local success, err = os.remove(lfile_path)
if not success then
vis:info('vis-lockfiles: ' .. err)
end
created_locks[lfile_path] = nil
end
vis.events.subscribe(vis.events.FILE_OPEN, function(file)
if not file.path then
return
end
local lfile_path = lock_file_path(file.path)
if not create_lock_file(lfile_path) and not confirm(lfile_path) then
os.exit(1)
end
end)
vis.events.subscribe(vis.events.FILE_CLOSE, function(file)
if not file.path then
return
end
local lfile_path = lock_file_path(file.path)
if created_locks[lfile_path] then
delete_lock_file(lfile_path)
end
end)
return M
|
