openproc - Man Page
initialize process information from /proc/
Synopsis
#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 memory 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 determines 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 information 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_FILLARG
equivalent to PROC_FILLCOM
- PROC_FILLCGROUP
alloc and fill in cgroup
- PROC_FILLSUPGRP
resolve supplementary group id -> group name
- PROC_FILLOOM
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