openproc

       #include <proc/readproc.h>

       PROCTAB* openproc (int flags, ... );
       void closeproc (PROCTAB* PT);

SYNOPSIS
       The openproc function initializes a PROCTAB structure which can be used
       by iterated readproc calls to get  information  on  current  processes.
       Depending on flags, openproc may need a second argument or a second and
       third argument (see below).

       closeproc closes all files opened by openproc and deallocates the  mem-
       ory allocated by openproc.

       The PROCTAB structure is defined in <proc/readproc.h>

RETURN VALUE
       openproc  returns a pointer to a PROCTAB structure, or NULL if an error
       occurs. This usually means that /proc cannot be read by the process.

FLAGS
       The behaviour of openproc is controlled by the following set of  flags,
       which  may  be ORed together. There are three different kinds of flags.
       The first group of flags determins which  information  gets  read  from
       /proc/#pid  for  each process. The second group of flags (of which only
       one can be enacted for a opendir call) restricts which processes infor-
       mation  is read for by providing a list of criteria. The third group of
       flags restricts this as well, but doesn't need arguments. These may  be
       used together again.

       PROC_FILLMEM
            read information from /proc/#pid/statm

       PROC_FILLCOM
            allocate   cmdline  part  of  proc_t  and  read  information  from
            /proc/#pid/cmdline

       PROC_FILLENV
            allocate  environ  part  of  proc_t  and  read  information   from
            /proc/#pid/environ

       PROC_FILLUSR
            resolve user ids to names via /etc/passwd

       PROC_FILLGRP
            resolve group ids to names via /etc/group

       PROC_FILLSTATUS
            read information from /proc/#pid/status

       PROC_FILLSTAT
            read information from /proc/#pid/stat

       PROC_FILLWCHAN
            fill in proc_t oom_score and oom_adj

       PROC_FILLNS
            fill in proc_t namespace information

       PROC_FILLSYSTEMD
            fill in proc_t systemd information

       PROC_LOOSE_TASKS
            threat threads as if they were processes

       PROC_PID (2nd argument pid_t* pidlist)
            lookup  only processes whose pid is contained in pidlist (the list
            is terminated with 0)

       PROC_UID (arguments uid_t* uidlist, int n)
            lookup only processes whose user id is contained in uidlist (where
            n is the number of uids contained in the list)

       PROC_EDITCGRPCVT
            edit cgroup as single vector

       PROC_EDITCMDLCVT
            edit cmdline as single vector

       PROC_EDITENVRCVT
            edit environ as single vector

NOTE
       Only one of the flags needing additional arguments (PROC_{PID,UID}) may
       be used at a time.

SEE ALSO
       readproc(3), readproctab(3), /proc/, /usr/include/proc/readproc.h,

REPORTING BUGS
       Please send bug reports to <procps@freelists.org>

Linux Manpage                    14 July 2014                      OPENPROC(3)
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