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-rw-r--r--asyncshell.lua63
1 files changed, 63 insertions, 0 deletions
diff --git a/asyncshell.lua b/asyncshell.lua
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--- /dev/null
+++ b/asyncshell.lua
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+-- Asynchronous io.popen for Awesome WM.
+-- How to use...
+-- ...asynchronously:
+-- asyncshell.request('wscript -Kiev', function(f) wwidget.text = f:read("*l") end)
+-- ...synchronously
+-- wwidget.text = asyncshell.demand('wscript -Kiev', 5):read("*l") or "Error"
+
+asyncshell = {}
+asyncshell.request_table = {}
+asyncshell.id_counter = 0
+asyncshell.file_template = '/tmp/asyncshellreq'
+
+os.execute('rm -f /tmp/myaw2.log')
+local nprint = function(t) os.execute("echo '" .. t .. "' >> /tmp/myaw2.log") end
+
+-- Returns next tag - unique identifier of the request
+local function next_id()
+ asyncshell.id_counter = (asyncshell.id_counter + 1) % 100000
+ return asyncshell.id_counter
+end
+
+-- Sends an asynchronous request for an output of the shell command.
+-- @param command Command to be executed and taken output from
+-- @param callback Function of one argument to be called when the command finishes
+-- @return Request ID
+function asyncshell.request(command, callback)
+ local id = next_id()
+ local tmpfname = asyncshell.file_template .. id
+ asyncshell.request_table[id] = {callback = callback}
+ local req =
+ string.format("bash -c '%s > %s; " ..
+ 'echo "asyncshell.deliver(%s)" | ' ..
+ "awesome-client'", string.gsub(command, "'", "'\\''"), tmpfname, id, tmpfname)
+ awful.util.spawn(req)
+ return id
+end
+
+-- Calls the remembered callback function on the output of the shell
+-- command.
+-- @param id Request ID
+-- @param output The output file of the shell command to be delievered
+function asyncshell.deliver(id)
+ if asyncshell.request_table[id] then
+ local output = io.open(asyncshell.file_template .. id, 'r')
+ asyncshell.request_table[id].callback(output)
+ end
+end
+
+-- Sends a synchronous request for an output of the command. Waits for
+-- the output, but if the given timeout expires returns nil.
+-- @param command Command to be executed and taken output from
+-- @param timeout Maximum amount of time to wait for the result
+-- @return File handler on success, nil otherwise
+function asyncshell.demand(command, timeout)
+ local id = next_id()
+ local tmpfname = asyncshell.file_template .. id
+ local f = io.popen(string.format("(%s > %s; echo asyncshell_done) & (sleep %s; echo asynchell_timeout)",
+ command, tmpfname, timeout))
+ local result = f:read("*line")
+ if result == "asyncshell_done" then
+ return io.open(tmpfname)
+ end
+end \ No newline at end of file