diff options
Diffstat (limited to 'asyncshell.lua')
| -rw-r--r-- | asyncshell.lua | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/asyncshell.lua b/asyncshell.lua new file mode 100644 index 0000000..63234c6 --- /dev/null +++ b/asyncshell.lua @@ -0,0 +1,63 @@ +-- 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
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