diff options
Diffstat (limited to 'lib/procps.lua')
-rw-r--r-- | lib/procps.lua | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/procps.lua b/lib/procps.lua new file mode 100644 index 0000000..d05ee14 --- /dev/null +++ b/lib/procps.lua @@ -0,0 +1,71 @@ + +module(..., package.seeall) + +require("posix") + +-- the following methods are available: +-- /proc/<pid>/stat the comm field (2nd) field contains name but only up +-- to 15 chars. does not resolve links +-- +-- /proc/<pid>/cmdline argv[0] contains the command. However if it is a script +-- then will the interpreter show up +-- +-- /proc/<pid>/exe link to exe file. this will resolv links +-- +-- returns list of all pids for given exe name + +--[[ +-- gives lots of false positives for busybox +local function is_exe(path, name) + local f = posix.readlink(path.."/exe") + if f and (f == name or posix.basename(f) == name) then + return true + else + return false + end +end +]]-- + + +local function is_stat(path, name) + local f = io.open(path.."/stat") + local line = f:read() + local p = string.match(line, "^%d+ %((%d+)%)") + f:close() + if p ~= nil and string.len(name) <= 15 and p == name then + return true + else + return false + end +end + +local function is_cmdline(path, name) + local f = io.open(path.."/cmdline") + if f == nil then + return false + end + local line = f:read() + f:close() + if line == nil then + return false + end + local arg0 = string.gsub(line, string.char(0)..".*", "") + return posix.basename(arg0) == name +end + +function pidof(name) + local pids = {} + local i, j + + for i,j in pairs(posix.glob("/proc/[0-9]*")) do + local pid = tonumber(posix.basename(j)) + if is_stat(j, name) or is_cmdline(j, name) then + table.insert(pids, pid) + end + end + if #pids == 0 then + pids = nil + end + return pids +end + |