Very Computer

Hi,

I am looking for a method to get a process-executable-name from a pid. Any
ideas?

Best regards
Stefan

[[ PLEASE DON'T SEND ME EMAIL COPIES OF POSTINGS ]]

man proc(4)

read /proc/pid/psinfo

The actual executable itself can be found as:

/proc/pid/object/a.out

Casper
--
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

If you're working on the command line, try the following:
ps -o pid -o comm | grep PID | cut -d' ' -f3
where PID is the known pid

If you're talking about doing this from C code:
system("ps -o pid -o comm | grep 1367 | cut -d' ' -f3 > outifle");
then open and read the file "outfile"  (might work...)

Good luck,
Tim

Quote:>If you're working on the command line, try the following:
>ps -o pid -o comm | grep PID | cut -d' ' -f3
>where PID is the known pid

if you know the pid why would you grep a complete list for it?  just have
ps display only that pid's information.  (besides, your grep would match
any process who's "command" is also that number -- unlikely, but not
impossible.)  and by doing that and dropping the heading line you don't
need either grep or cut, i.e., just

  ps -h -o comm -p PID

Quote:>If you're talking about doing this from C code:
>system("ps -o pid -o comm | grep 1367 | cut -d' ' -f3 > outifle");
>then open and read the file "outfile"  (might work...)

it's easier and somewhat safer to use popen, e.g.,

  char buf[100] = {0};
  FILE *p = popen("ps -h -o comm -p 1367", "r");
  if (NULL == p) perror("popen");
  else {
    if (NULL == fgets(buf,sizeof buf,p)) if (0 != errno) perror("fgets");
    pclose(p);
  }

it would be much safer to use exec, but there's more code you have to write
to handle it, e.g.,

  char buf[100] = {0}; int p[2];
  if (0 > pipe(p)) perror("pipe");
  else {
    pid_t pid = fork();
    if ((pid_t)0 > pid) perror("fork");
    else if ((pid_t)0 == pid) {
      if (0 > dup2(p[1],STDOUT_FILENO)) perror("dup2");
      else execl("/bin/ps","ps","-h","-o","comm","-p","1367",NULL);
      _exit(127);
    }
    else {
      pid_t n;
      do n = waitpid(pid,NULL,0); while ((pid_t)0 > n && EINTR == errno);
      if (n != pid) error("waitpid");
      else {
        FILE *f = fdopen(p[0],"r");
        if (NULL == f) perror("fdopen");
        else {
          if (NULL == fgets(buf,sizeof buf,f)) if (0 != errno) perror("fgets");
          if (0 > fclose(f)) perror("fclose");
        }
      }
    }
    close(p[0]); close(p[1]);
  }

note: i've excluded some stuff, such as signal handling and closing unused
pipe fd's, but is the basic form.

--
okay, have a sig then