Re: How to detect whether a process is running, on Linux, in the manner of 'pidof'?

[Nicholas Joll <nicholasjoll@...>]

    Dear all
    
    I have had a couple of replies and one of my respondents - when I
    emailed him directly - suggested that I should respond to replies on
    list. (I am new to this list. One of the few lists that I used
    before wanted replies off-list.)
    
    So . .
    
    Another person suggested that I somehow query Linux's /proc
    filesystem. The idea was: that is what pidof does. Well, I know how
    to do elementary file-handing in lua, but what do I seek in /proc?
    Surely there's an easier way for me to tell whether a process is
    running than by determining how pidof works and reimplementing its C
    code, myself, in lua. (Please note also that, as I said in my first
    email, I do not want to call pidof _from_ lua. That is what my code
    does already, and it works, but so doing uses too many resources for
    my use-case.)
    
    One respondent suggested that I could 'try sending signal 0 to the
    process using the kill(2) system call'. OK; but how do I do that in
    lua? I see (from
      this documentation) that the luaposix module has a 'kill'
    command. So, so long as I can get an informative number back from
    that call, it should work. I will try it.
    
    Yours
    
    Nick