PROCPS_MISC(3)

NAME
procps_misc - API for miscellaneous information in the /proc filesystem

SYNOPSIS
#include <libproc2/misc.h>

Platform Particulars

    long         procps_cpu_count (void);
    long         procps_hertz_get (void);
    unsigned int procps_pid_length (void);
    int          procps_linux_version (void);

Runtime Particulars

    int   procps_loadavg (double *av1, double *av5, double *av15);
    int   procps_uptime (double *uptime_secs, double *idle_secs);
    char *procps_uptime_sprint (void);
    char *procps_uptime_sprint_short (void);

Namespace Particulars

    int         procps_ns_get_id (const char *name);
    const char *procps_ns_get_name (int id);
    int         procps_ns_read_pid (int pid, struct procps_ns *nsp);

Link with -lproc2.

DESCRIPTION
procps_cpu_count() returns the number of CPUs that are currently online as sysconf(_SC_NPROCESSORS_ONLY) or an assumed 1.

procps_hertz_get() returns the number of clock ticks per second as sysconf(_SC_CLK_TCK) or an assumed 100. Dividing tics by this value yields seconds.

procps_pid_length() returns the maximum string length for a PID on the system. For example, if the largest possible PID value on was 123, then the length would be 3. If the file /proc/sys/kernel/pid_max is unreadable, the value is assumed to be 5.

procps_linux_version() returns the current Linux version as an encoded integer. On non-Linux systems that have an emulated proc filesystem this function returns the version of the Linux emulation instead. The version consists of three positive integers representing the major, minor and patch levels. The following macros are provided for encoding a given Linux version or separating out the components of the current version.

    LINUX_VERSION( major , minor , patch )

    LINUX_VERSION_MAJOR( ver )

    LINUX_VERSION_MINOR( ver )

    LINUX_VERSION_PATCH( ver )

procps_loadavg() fetches the system load average and puts the 1, 5 and 15 minute averages into location(s) specified by any pointer which is not NULL.

procps_uptime() returns uptime and/or idle seconds into location(s) specified by any pointer which is not NULL. The sprint varieties return a human-readable string in one of two forms.

    HH:MM:SS up HH:MM, # users, load average: 1, 5, 15 MM averages

    up HH, MM

procps_ns_get_id() returns the integer id (enum namespace_type) of the namespace for the given namespace name.

procps_ns_get_name() returns the name of the namespace for the given id (enum namespace_type).

procps_ns_read_pid() returns the inodes for the namespaces of the given process in the procps_ns structure pointed to by nsp. Those inodes will appear in the order proscribed by enum namespace_type.

    enum namespace_type {
        PROCPS_NS_CGROUP,
        PROCPS_NS_IPC,
        PROCPS_NS_MNT,
        PROCPS_NS_NET,
        PROCPS_NS_PID,
        PROCPS_NS_TIME,
        PROCPS_NS_USER,
        PROCPS_NS_UTS
    };

RETURN VALUE

  Functions Returning an `int' or `long'
An error will be indicated by a negative number that is always the inverse of some well known errno.h value.

  Functions Returning an `address'
An error will be indicated by a NULL return pointer with the reason found in the formal errno value.

FILES

/proc/loadavg
    The raw values for load average.

/proc/sys/kernel/osrelease
    Contains the release version of the Linux kernel or proc filesystem.

/proc/sys/kernel/pid_max
    Contains the value at which PIDs wrap around, one greater than the maximum PID value.

/proc/uptime
    The raw values for uptime and idle time.

/proc/<PID>/ns
    contains the set of namespaces for a particular PID.

SEE ALSO
procps(3), procps_pids(3), proc(5).