mirror of https://github.com/lcpz/lain.git
81 lines
2.8 KiB
Lua
81 lines
2.8 KiB
Lua
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--[[
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Licensed under GNU General Public License v2
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* (c) 2013, Alexander Yakushev
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--]]
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-- Asynchronous io.popen for Awesome WM.
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-- How to use...
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-- ...asynchronously:
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-- asyncshell.request('wscript -Kiev', function(f) wwidget.text = f:read("*l") end)
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-- ...synchronously
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-- wwidget.text = asyncshell.demand('wscript -Kiev', 5):read("*l") or "Error"
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local spawn = require('awful.util').spawn
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asyncshell = {}
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asyncshell.request_table = {}
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asyncshell.id_counter = 0
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asyncshell.folder = "/tmp/asyncshell"
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asyncshell.file_template = asyncshell.folder .. '/req'
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-- Create a directory for asynchell response files
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os.execute("mkdir -p " .. asyncshell.folder)
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-- Returns next tag - unique identifier of the request
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local function next_id()
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asyncshell.id_counter = (asyncshell.id_counter + 1) % 100000
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return asyncshell.id_counter
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end
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-- Sends an asynchronous request for an output of the shell command.
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-- @param command Command to be executed and taken output from
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-- @param callback Function to be called when the command finishes
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-- @return Request ID
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function asyncshell.request(command, callback)
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local id = next_id()
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local tmpfname = asyncshell.file_template .. id
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asyncshell.request_table[id] = {callback = callback}
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local req =
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string.format("bash -c '%s > %s; " ..
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'echo "asyncshell.deliver(%s)" | ' ..
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"awesome-client' 2> /dev/null",
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string.gsub(command, "'", "'\\''"), tmpfname,
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id, tmpfname)
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spawn(req, false)
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return id
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end
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-- Calls the remembered callback function on the output of the shell
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-- command.
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-- @param id Request ID
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-- @param output The output file of the shell command to be delievered
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function asyncshell.deliver(id)
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if asyncshell.request_table[id] and
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asyncshell.request_table[id].callback then
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local output = io.open(asyncshell.file_template .. id, 'r')
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asyncshell.request_table[id].callback(output)
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end
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end
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-- Sends a synchronous request for an output of the command. Waits for
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-- the output, but if the given timeout expires returns nil.
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-- @param command Command to be executed and taken output from
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-- @param timeout Maximum amount of time to wait for the result
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-- @return File handler on success, nil otherwise
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function asyncshell.demand(command, timeout)
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local id = next_id()
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local tmpfname = asyncshell.file_template .. id
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local f = io.popen(string.format("(%s > %s; echo asyncshell_done) & " ..
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"(sleep %s; echo asynchell_timeout)",
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command, tmpfname, timeout))
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local result = f:read("*line")
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if result == "asyncshell_done" then
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return io.open(tmpfname)
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end
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end
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return asyncshell
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