sys_info/
lib.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
//! #Introduction
//! This crate focuses on geting system information.
//!
//! For now it supports Linux, Mac OS X and Windows.
//! And now it can get information of kernel/cpu/memory/disk/load/hostname and so on.
//!

extern crate libc;

use std::ffi;
use std::fmt;
use std::io::{self, Read};
use std::fs::File;
#[cfg(any(target_os = "windows", target_vendor = "apple", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
use std::os::raw::c_char;
#[cfg(not(any(target_os = "windows", target_os = "linux")))]
use std::os::raw::{c_int, c_double};

#[cfg(any(target_vendor = "apple", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
use libc::sysctl;
#[cfg(any(target_vendor = "apple", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
use std::mem::size_of_val;
#[cfg(any(target_vendor = "apple", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
use std::ptr::null_mut;
#[cfg(not(target_os = "windows"))]
use libc::timeval;
#[cfg(any(target_os = "solaris", target_os = "illumos"))]
use std::time::SystemTime;
#[cfg(target_os = "linux")]
use std::collections::HashMap;

#[cfg(any(target_os = "solaris", target_os = "illumos"))]
mod kstat;

#[cfg(any(target_vendor = "apple", target_os="freebsd", target_os = "openbsd", target_os = "netbsd"))]
static OS_CTL_KERN: libc::c_int = 1;
#[cfg(any(target_vendor = "apple", target_os="freebsd", target_os = "openbsd", target_os = "netbsd"))]
static OS_KERN_BOOTTIME: libc::c_int = 21;

/// System load average value.
#[repr(C)]
#[derive(Debug)]
pub struct LoadAvg {
    /// Average load within one minutes.
    pub one: f64,
    /// Average load within five minutes.
    pub five: f64,
    /// Average load within fifteen minutes.
    pub fifteen: f64,
}

/// System memory information.
#[repr(C)]
#[derive(Debug)]
pub struct MemInfo {
    /// Total physical memory.
    pub total: u64,
    pub free: u64,
    pub avail: u64,

    pub buffers: u64,
    pub cached: u64,

    /// Total swap memory.
    pub swap_total: u64,
    pub swap_free: u64,
}

/// The os release info of Linux.
///
/// See [man os-release](https://www.freedesktop.org/software/systemd/man/os-release.html).
#[derive(Debug)]
#[derive(Default)]
pub struct LinuxOSReleaseInfo {
    /// A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_" and "-")
    /// identifying the operating system, excluding any version information and suitable for
    /// processing by scripts or usage in generated filenames.
    ///
    /// Note that we don't verify that the string is lower-case and can be used in file-names. If
    /// the /etc/os-release file has an invalid value, you will get this value.
    ///
    /// If not set, defaults to "ID=linux". Use `self.id()` to fallback to the default.
    ///
    /// Example: "fedora" or "debian".
    pub id: Option<String>,

    /// A space-separated list of operating system identifiers in the same syntax as the ID=
    /// setting. It should list identifiers of operating systems that are closely related to the
    /// local operating system in regards to packaging and programming interfaces, for example
    /// listing one or more OS identifiers the local OS is a derivative from. An OS should
    /// generally only list other OS identifiers it itself is a derivative of, and not any OSes
    /// that are derived from it, though symmetric relationships are possible. Build scripts and
    /// similar should check this variable if they need to identify the local operating system and
    /// the value of ID= is not recognized. Operating systems should be listed in order of how
    /// closely the local operating system relates to the listed ones, starting with the closest.
    ///
    /// This field is optional.
    ///
    /// Example: for an operating system with `ID=centos`, an assignment of `ID_LIKE="rhel fedora"`
    /// would be appropriate. For an operating system with `ID=ubuntu`, an assignment of
    /// `ID_LIKE=debian` is appropriate.
    pub id_like: Option<String>,

    /// A string identifying the operating system, without a version component, and suitable for
    /// presentation to the user.
    ///
    /// If not set, defaults to "NAME=Linux".Use `self.id()` to fallback to the default.
    ///
    /// Example: "Fedora" or "Debian GNU/Linux".
    pub name: Option<String>,

    /// A pretty operating system name in a format suitable for presentation to the user. May or
    /// may not contain a release code name or OS version of some kind, as suitable.
    ///
    /// If not set, defaults to "Linux". Use `self.id()` to fallback to the default.
    ///
    /// Example: "Fedora 17 (Beefy Miracle)".
    pub pretty_name: Option<String>,

    /// A string identifying the operating system version, excluding any OS name information,
    /// possibly including a release code name, and suitable for presentation to the user.
    ///
    /// This field is optional.
    ///
    /// Example: "17" or "17 (Beefy Miracle)"
    pub version: Option<String>,

    /// A lower-case string (mostly numeric, no spaces or other characters outside of 0–9, a–z,
    /// ".", "_" and "-") identifying the operating system version, excluding any OS name
    /// information or release code name, and suitable for processing by scripts or usage in
    /// generated filenames.
    ///
    /// This field is optional.
    ///
    /// Example: "17" or "11.04".
    pub version_id: Option<String>,

    /// A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_" and "-")
    /// identifying the operating system release code name, excluding any OS name information or
    /// release version, and suitable for processing by scripts or usage in generated filenames.
    ///
    /// This field is optional and may not be implemented on all systems.
    ///
    /// Examples: "buster", "xenial".
    pub version_codename: Option<String>,

    /// A suggested presentation color when showing the OS name on the console. This should be
    /// specified as string suitable for inclusion in the ESC [ m ANSI/ECMA-48 escape code for
    /// setting graphical rendition.
    ///
    /// This field is optional.
    ///
    /// Example: "0;31" for red, "1;34" for light blue, or "0;38;2;60;110;180" for Fedora blue.
    pub ansi_color: Option<String>,

    /// A string, specifying the name of an icon as defined by freedesktop.org Icon Theme
    /// Specification. This can be used by graphical applications to display an operating
    /// system's or distributor's logo.
    ///
    /// This field is optional and may not necessarily be implemented on all systems.
    ///
    /// Examples: "LOGO=fedora-logo", "LOGO=distributor-logo-opensuse".
    pub logo: Option<String>,

    /// A CPE name for the operating system, in URI binding syntax, following the Common Platform
    /// Enumeration Specification as proposed by the NIST.
    ///
    /// This field is optional.
    ///
    /// Example: "cpe:/o:fedoraproject:fedora:17".
    pub cpe_name: Option<String>,

    /// A string uniquely identifying the system image used as the origin for a distribution (it is
    /// not updated with system updates). The field can be identical between different VERSION_IDs
    /// as BUILD_ID is an only a unique identifier to a specific version. Distributions that
    /// release each update as a new version would only need to use VERSION_ID as each build is
    /// already distinct based on the VERSION_ID.
    ///
    /// This field is optional.
    ///
    /// Example: "2013-03-20.3" or "BUILD_ID=201303203".
    pub build_id: Option<String>,

    /// A string identifying a specific variant or edition of the operating system suitable for
    /// presentation to the user. This field may be used to inform the user that the configuration
    /// of this system is subject to a specific divergent set of rules or default configuration
    /// settings.
    ///
    /// This field is optional and may not be implemented on all systems.
    ///
    /// Examples: "Server Edition", "Smart Refrigerator Edition".
    ///
    /// Note: this field is for display purposes only. The VARIANT_ID field should be used for
    /// making programmatic decisions.
    pub variant: Option<String>,

    /// A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_" and "-"),
    /// identifying a specific variant or edition of the operating system. This may be interpreted
    /// by other packages in order to determine a divergent default configuration.
    ///
    /// This field is optional and may not be implemented on all systems.
    ///
    /// Examples: "server", "embedded".
    pub variant_id: Option<String>,

    /// HOME_URL= should refer to the homepage of the operating system, or alternatively some homepage of
    /// the specific version of the operating system.
    ///
    /// These URLs are intended to be exposed in "About this system" UIs behind links with captions
    /// such as "About this Operating System", "Obtain Support", "Report a Bug", or "Privacy
    /// Policy". The values should be in RFC3986 format, and should be "http:" or "https:" URLs,
    /// and possibly "mailto:" or "tel:". Only one URL shall be listed in each setting. If multiple
    /// resources need to be referenced, it is recommended to provide an online landing page
    /// linking all available resources.
    ///
    /// Example: "https://fedoraproject.org/".
    pub home_url: Option<String>,

    /// DOCUMENTATION_URL= should refer to the main documentation page for this operating system.
    ///
    /// See also `home_url`.
    pub documentation_url: Option<String>,

    /// SUPPORT_URL= should refer to the main support page for the operating system, if there is
    /// any. This is primarily intended for operating systems which vendors provide support for.
    ///
    /// See also `home_url`.
    pub support_url: Option<String>,

    /// BUG_REPORT_URL= should refer to the main bug reporting page for the operating system, if
    /// there is any. This is primarily intended for operating systems that rely on community QA.
    ///
    /// Example: "https://bugzilla.redhat.com/".
    ///
    /// See also `home_url`.
    pub bug_report_url: Option<String>,

    /// PRIVACY_POLICY_URL= should refer to the main privacy policy page for the operating system,
    /// if there is any. These settings are optional, and providing only some of these settings is
    /// common.
    ///
    /// See also `home_url`.
    pub privacy_policy_url: Option<String>,
}

macro_rules! os_release_defaults {
    (
        $(
            $(#[$meta:meta])*
            $vis:vis fn $field:ident => $default:literal
        )*
    ) => {
        $(
            $(#[$meta])*
            $vis fn $field(&self) -> &str {
                match self.$field.as_ref() {
                    Some(value) => value,
                    None => $default,
                }
            }
        )*
    }
}

impl LinuxOSReleaseInfo {
    os_release_defaults!(
        /// Returns the value of `self.id` or, if `None`, "linux" (the default value).
        pub fn id => "linux"
        /// Returns the value of `self.name` or, if `None`, "Linux" (the default value).
        pub fn name => "Linux"
        /// Returns the value of `self.pretty_name` or, if `None`, "Linux" (the default value).
        pub fn pretty_name => "Linux"
    );
}

/// Disk information.
#[repr(C)]
#[derive(Debug)]
pub struct DiskInfo {
    pub total: u64,
    pub free: u64,
}

/// Error types
#[derive(Debug)]
pub enum Error {
    UnsupportedSystem,
    ExecFailed(io::Error),
    IO(io::Error),
    SystemTime(std::time::SystemTimeError),
    General(String),
    Unknown,
}

impl fmt::Display for Error {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        use self::Error::*;
        match *self {
            UnsupportedSystem => write!(fmt, "System is not supported"),
            ExecFailed(ref e) => write!(fmt, "Execution failed: {}", e),
            IO(ref e) => write!(fmt, "IO error: {}", e),
            SystemTime(ref e) => write!(fmt, "System time error: {}", e),
            General(ref e) => write!(fmt, "Error: {}", e),
            Unknown => write!(fmt, "An unknown error occurred"),
        }
    }
}

impl std::error::Error for Error {
    fn description(&self) -> &str {
        use self::Error::*;
        match *self {
            UnsupportedSystem => "unsupported system",
            ExecFailed(_) => "execution failed",
            IO(_) => "io error",
            SystemTime(_) => "system time",
            General(_) => "general error",
            Unknown => "unknown error",
        }
    }

    fn cause(&self) -> Option<&dyn std::error::Error> {
        use self::Error::*;
        match *self {
            UnsupportedSystem => None,
            ExecFailed(ref e) => Some(e),
            IO(ref e) => Some(e),
            SystemTime(ref e) => Some(e),
            General(_) => None,
            Unknown => None,
        }
    }
}

impl From<io::Error> for Error {
    fn from(e: io::Error) -> Error {
        Error::IO(e)
    }
}

impl From<std::time::SystemTimeError> for Error {
    fn from(e: std::time::SystemTimeError) -> Error {
        Error::SystemTime(e)
    }
}

impl From<Box<dyn std::error::Error>> for Error {
    fn from(e: Box<dyn std::error::Error>) -> Error {
        Error::General(e.to_string())
    }
}

extern "C" {
    #[cfg(any(target_vendor = "apple", target_os = "windows"))]
    fn get_os_type() -> *const i8;
    #[cfg(any(target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    fn get_os_release() -> *const i8;

    #[cfg(all(not(any(target_os = "solaris", target_os = "illumos", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")), any(unix, windows)))]
    fn get_cpu_num() -> u32;
    #[cfg(any(all(target_vendor = "apple", not(any(target_arch = "aarch64", target_arch = "arm"))), target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    fn get_cpu_speed() -> u64;

    #[cfg(target_os = "windows")]
    fn get_loadavg() -> LoadAvg;
    #[cfg(any(target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    fn get_proc_total() -> u64;

    #[cfg(any(target_vendor = "apple", target_os = "windows"))]
    fn get_mem_info() -> MemInfo;
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    fn get_mem_info_bsd(mi: &mut MemInfo) ->i32;

    #[cfg(any(target_os = "linux", target_vendor = "apple", target_os = "windows"))]
    fn get_disk_info() -> DiskInfo;
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    fn get_disk_info_bsd(di: &mut DiskInfo) -> i32;
}


/// Get operation system type.
///
/// Such as "Linux", "Darwin", "Windows".
pub fn os_type() -> Result<String, Error> {
    #[cfg(target_os = "linux")]
    {
        let mut s = String::new();
        File::open("/proc/sys/kernel/ostype")?.read_to_string(&mut s)?;
        s.pop(); // pop '\n'
        Ok(s)
    }
    #[cfg(any(target_vendor = "apple", target_os = "windows"))]
    {
        let typ = unsafe { ffi::CStr::from_ptr(get_os_type() as *const c_char).to_bytes() };
        Ok(String::from_utf8_lossy(typ).into_owned())
    }
    #[cfg(target_os = "solaris")]
    {
        Ok("solaris".to_string())
    }
    #[cfg(target_os = "illumos")]
    {
        Ok("illumos".to_string())
    }
    #[cfg(target_os = "freebsd")]
    {
        Ok("freebsd".to_string())
    }
    #[cfg(target_os = "openbsd")]
    {
        Ok("openbsd".to_string())
    }
    #[cfg(target_os = "netbsd")]
    {
        Ok("netbsd".to_string())
    }
    #[cfg(not(any(target_os = "linux", target_vendor = "apple", target_os = "windows", target_os = "solaris", target_os = "illumos", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get operation system release version.
///
/// Such as "3.19.0-gentoo"
pub fn os_release() -> Result<String, Error> {
    #[cfg(target_os = "linux")]
    {
        let mut s = String::new();
        File::open("/proc/sys/kernel/osrelease")?.read_to_string(&mut s)?;
        s.pop(); // pop '\n'
        Ok(s)
    }
    #[cfg(any(target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
        unsafe {
	    let rp = get_os_release() as *const c_char;
	    if rp == std::ptr::null() {
		Err(Error::Unknown)
	    } else {
		let typ = ffi::CStr::from_ptr(rp).to_bytes();
		Ok(String::from_utf8_lossy(typ).into_owned())
	    }
	}
    }
    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
    {
        let release: Option<String> = unsafe {
            let mut name: libc::utsname = std::mem::zeroed();
            if libc::uname(&mut name) < 0 {
                None
            } else {
                let cstr = std::ffi::CStr::from_ptr(name.release.as_mut_ptr());
                Some(cstr.to_string_lossy().to_string())
            }
        };
        match release {
            None => Err(Error::Unknown),
            Some(release) => Ok(release),
        }
    }
    #[cfg(not(any(target_os = "linux", target_vendor = "apple", target_os = "windows", target_os = "solaris", target_os = "illumos", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get the os release note of Linux
///
/// Information in /etc/os-release, such as name and version of distribution.
///
/// See `LinuxOSReleaseInfo` for more documentation.
pub fn linux_os_release() -> Result<LinuxOSReleaseInfo, Error> {
    if !cfg!(target_os = "linux") {
        return Err(Error::UnsupportedSystem);
    }

    let mut s = String::new();
    File::open("/etc/os-release")?.read_to_string(&mut s)?;

    let mut info: LinuxOSReleaseInfo = Default::default();
    for l in s.split('\n') {
        match parse_line_for_linux_os_release(l.trim().to_string()) {
            Some((key, value)) =>
                match (key.as_ref(), value) {
                    ("ID", val) => info.id = Some(val),
                    ("ID_LIKE", val) => info.id_like = Some(val),
                    ("NAME", val) => info.name = Some(val),
                    ("PRETTY_NAME", val) => info.pretty_name = Some(val),

                    ("VERSION", val) => info.version = Some(val),
                    ("VERSION_ID", val) => info.version_id = Some(val),
                    ("VERSION_CODENAME", val) => info.version_codename = Some(val),

                    ("ANSI_COLOR", val) => info.ansi_color = Some(val),
                    ("LOGO", val) => info.logo = Some(val),

                    ("CPE_NAME", val) => info.cpe_name = Some(val),
                    ("BUILD_ID", val) => info.build_id = Some(val),
                    ("VARIANT", val) => info.variant = Some(val),
                    ("VARIANT_ID", val) => info.variant_id = Some(val),

                    ("HOME_URL", val) => info.home_url = Some(val),
                    ("BUG_REPORT_URL", val) => info.bug_report_url = Some(val),
                    ("SUPPORT_URL", val) => info.support_url = Some(val),
                    ("DOCUMENTATION_URL", val) => info.documentation_url = Some(val),
                    ("PRIVACY_POLICY_URL", val) => info.privacy_policy_url = Some(val),
                    _ => {}
                }
            None => {}
        }
    }

    Ok(info)
}

fn parse_line_for_linux_os_release(l: String) -> Option<(String, String)> {
    let words: Vec<&str> = l.splitn(2, '=').collect();
    if words.len() < 2 {
        return None
    }
    let mut trim_value = String::from(words[1]);

    if trim_value.starts_with('"') {
        trim_value.remove(0);
    }
    if trim_value.ends_with('"') {
        let len = trim_value.len();
        trim_value.remove(len - 1);
    }

    return Some((String::from(words[0]), trim_value))
}

/// Get cpu num quantity.
///
/// Notice, it returns the logical cpu quantity.
pub fn cpu_num() -> Result<u32, Error> {
    #[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
        let ret = unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) };
        if ret < 1 || ret as i64 > std::u32::MAX as i64 {
            Err(Error::IO(io::Error::last_os_error()))
        } else {
            Ok(ret as u32)
        }
    }
    #[cfg(all(not(any(target_os = "solaris", target_os = "illumos", target_os="freebsd", target_os = "openbsd", target_os = "netbsd")), any(unix, windows)))]
    {
        unsafe { Ok(get_cpu_num()) }
    }
    #[cfg(not(any(target_os = "solaris", target_os = "illumos", unix, windows)))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get cpu speed.
///
/// Such as 2500, that is 2500 MHz.
pub fn cpu_speed() -> Result<u64, Error> {
    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
    {
       Ok(kstat::cpu_mhz()?)
    }
    #[cfg(target_os = "linux")]
    {
        // /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
        let mut s = String::new();
        File::open("/proc/cpuinfo")?.read_to_string(&mut s)?;

        let find_cpu_mhz = s.split('\n').find(|line|
            line.starts_with("cpu MHz\t") ||
                line.starts_with("BogoMIPS") ||
                line.starts_with("clock\t") ||
                line.starts_with("bogomips per cpu")
        );

        find_cpu_mhz.and_then(|line| line.split(':').last())
            .and_then(|val| val.replace("MHz", "").trim().parse::<f64>().ok())
            .map(|speed| speed as u64)
            .ok_or(Error::Unknown)
    }
    #[cfg(any(all(target_vendor = "apple", not(any(target_arch = "aarch64", target_arch = "arm"))), target_os = "windows"))]
    {
        unsafe { Ok(get_cpu_speed()) }
    }
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
	let res: u64 = unsafe { get_cpu_speed() };
	match res {
	    0 => Err(Error::IO(io::Error::last_os_error())),
	    _ => Ok(res),
	}
    }
    #[cfg(not(any(target_os = "solaris", target_os = "illumos", target_os = "linux", all(target_vendor = "apple", not(any(target_arch = "aarch64", target_arch = "arm"))), target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get system load average value.
///
/// Notice, on windows, one/five/fifteen of the LoadAvg returned are the current load.
pub fn loadavg() -> Result<LoadAvg, Error> {
    #[cfg(target_os = "linux")]
    {
        let mut s = String::new();
        File::open("/proc/loadavg")?.read_to_string(&mut s)?;
        let loads = s.trim().split(' ')
            .take(3)
            .map(|val| val.parse::<f64>().unwrap())
            .collect::<Vec<f64>>();
        Ok(LoadAvg {
            one: loads[0],
            five: loads[1],
            fifteen: loads[2],
        })
    }
    #[cfg(any(target_os = "solaris", target_os = "illumos", target_vendor = "apple", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
        let mut l: [c_double; 3] = [0f64; 3];
        if unsafe { libc::getloadavg(l.as_mut_ptr(), l.len() as c_int) } < 3 {
            Err(Error::Unknown)
        } else {
            Ok(LoadAvg {
                one: l[0],
                five: l[1],
                fifteen: l[2],
            })
        }
    }
    #[cfg(any(target_os = "windows"))]
    {
        Ok(unsafe { get_loadavg() })
    }
    #[cfg(not(any(target_os = "linux", target_os = "solaris", target_os = "illumos", target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get current processes quantity.
pub fn proc_total() -> Result<u64, Error> {
    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
    {
        Ok(kstat::nproc()?)
    }
    #[cfg(target_os = "linux")]
    {
        let mut s = String::new();
        File::open("/proc/loadavg")?.read_to_string(&mut s)?;
        s.split(' ')
            .nth(3)
            .and_then(|val| val.split('/').last())
            .and_then(|val| val.parse::<u64>().ok())
            .ok_or(Error::Unknown)
    }
    #[cfg(any(target_vendor = "apple", target_os = "windows"))]
    {
        Ok(unsafe { get_proc_total() })
    }
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
	let res: u64 = unsafe { get_proc_total() };
	match res {
	    0 => Err(Error::IO(io::Error::last_os_error())),
	    _ => Ok(res),
	}
    }
    #[cfg(not(any(target_os = "linux", target_os = "solaris", target_os = "illumos", target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

#[cfg(any(target_os = "solaris", target_os = "illumos"))]
fn pagesize() -> Result<u32, Error> {
    let ret = unsafe { libc::sysconf(libc::_SC_PAGESIZE) };
    if ret < 1 || ret > std::u32::MAX as i64 {
        Err(Error::Unknown)
    } else {
        Ok(ret as u32)
    }
}

/// Get memory information.
///
/// On Mac OS X and Windows, the buffers and cached variables of the MemInfo returned are zero.
pub fn mem_info() -> Result<MemInfo, Error> {
    #[cfg(target_os = "linux")]
    {
        let mut s = String::new();
        File::open("/proc/meminfo")?.read_to_string(&mut s)?;
        let mut meminfo_hashmap = HashMap::new();
        for line in s.lines() {
            let mut split_line = line.split_whitespace();
            let label = split_line.next();
            let value = split_line.next();
            if value.is_some() && label.is_some() {
                let label = label.unwrap().split(':').nth(0).ok_or(Error::Unknown)?;
                let value = value.unwrap().parse::<u64>().ok().ok_or(Error::Unknown)?;
                meminfo_hashmap.insert(label, value);
            }
        }
        let total = *meminfo_hashmap.get("MemTotal").ok_or(Error::Unknown)?;
        let free = *meminfo_hashmap.get("MemFree").ok_or(Error::Unknown)?;
        let buffers = *meminfo_hashmap.get("Buffers").ok_or(Error::Unknown)?;
        let cached = *meminfo_hashmap.get("Cached").ok_or(Error::Unknown)?;
        let avail = meminfo_hashmap.get("MemAvailable").map(|v| v.clone()).or_else(|| {
            let sreclaimable = *meminfo_hashmap.get("SReclaimable")?;
            let shmem = *meminfo_hashmap.get("Shmem")?;
            Some(free + buffers + cached + sreclaimable - shmem)
        }).ok_or(Error::Unknown)?;
        let swap_total = *meminfo_hashmap.get("SwapTotal").ok_or(Error::Unknown)?;
        let swap_free = *meminfo_hashmap.get("SwapFree").ok_or(Error::Unknown)?;
        Ok(MemInfo {
            total,
            free,
            avail,
            buffers,
            cached,
            swap_total,
            swap_free,
        })
    }
    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
    {
        let pagesize = pagesize()? as u64;
        let pages = kstat::pages()?;
        return Ok(MemInfo {
            total: pages.physmem * pagesize / 1024,
            avail: 0,
            free: pages.freemem * pagesize / 1024,
            cached: 0,
            buffers: 0,
            swap_total: 0,
            swap_free: 0,
        });
    }
    #[cfg(any(target_vendor = "apple", target_os = "windows"))]
    {
        Ok(unsafe { get_mem_info() })
    }
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
	let mut mi:MemInfo = MemInfo{total: 0, free: 0, avail: 0, buffers: 0,
				     cached: 0, swap_total: 0, swap_free: 0};
	let res: i32 = unsafe { get_mem_info_bsd(&mut mi) };
	match res {
	    -1 => Err(Error::IO(io::Error::last_os_error())),
	    0 => Ok(mi),
	    _ => Err(Error::Unknown),
	}
    }
    #[cfg(not(any(target_os = "linux", target_os = "solaris", target_os = "illumos", target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get disk information.
///
/// Notice, it just calculate current disk on Windows.
pub fn disk_info() -> Result<DiskInfo, Error> {
    #[cfg(any(target_os = "linux", target_vendor = "apple", target_os = "windows"))]
    {
        Ok(unsafe { get_disk_info() })
    }
    #[cfg(any(target_os = "freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
	let mut di:DiskInfo = DiskInfo{total: 0, free: 0};
	let res: i32 = unsafe { get_disk_info_bsd(&mut di) };
	match res {
	    -1 => Err(Error::IO(io::Error::last_os_error())),
	    0 => Ok(di),
	    _ => Err(Error::Unknown),
	}
    }
    #[cfg(not(any(target_os = "linux", target_vendor = "apple", target_os = "windows", target_os = "freebsd", target_os = "openbsd", target_os = "netbsd")))]
    {
        Err(Error::UnsupportedSystem)
    }
}

/// Get hostname.
#[cfg(target_family = "unix")]
pub fn hostname() -> Result<String, Error> {
    unsafe {
        let buf_size = libc::sysconf(libc::_SC_HOST_NAME_MAX) as usize;
        let mut buf = Vec::<u8>::with_capacity(buf_size + 1);
        if libc::gethostname(buf.as_mut_ptr() as *mut libc::c_char, buf_size) < 0 {
            return Err(Error::IO(io::Error::last_os_error()));
        }
        let hostname_len = libc::strnlen(buf.as_ptr() as *const libc::c_char, buf_size);
        buf.set_len(hostname_len);
        Ok(ffi::CString::new(buf).unwrap().into_string().unwrap())
    }
}

#[cfg(target_family = "windows")]
pub fn hostname() -> Result<String, Error> {
    use std::process::Command;
    Command::new("hostname")
        .output()
        .map_err(Error::ExecFailed)
        .map(|output| String::from_utf8(output.stdout).unwrap().trim().to_string())
}

/// Get system boottime
#[cfg(not(windows))]
pub fn boottime() -> Result<timeval, Error> {
    let mut bt = timeval {
        tv_sec: 0,
        tv_usec: 0
    };

    #[cfg(any(target_os = "linux", target_os="android"))]
    {
        let mut s = String::new();
        File::open("/proc/uptime")?.read_to_string(&mut s)?;
        let secs = s.trim().split(' ')
            .take(2)
            .map(|val| val.parse::<f64>().unwrap())
            .collect::<Vec<f64>>();
        bt.tv_sec = secs[0] as libc::time_t;
        bt.tv_usec = secs[1] as libc::suseconds_t;
	    return Ok(bt);
    }
    #[cfg(any(target_vendor = "apple", target_os="freebsd", target_os = "openbsd", target_os = "netbsd"))]
    {
        let mut mib = [OS_CTL_KERN, OS_KERN_BOOTTIME];
        let mut size: libc::size_t = size_of_val(&bt) as libc::size_t;
        unsafe {
            if sysctl(&mut mib[0], 2,
                   &mut bt as *mut timeval as *mut libc::c_void,
                   &mut size, null_mut(), 0) == -1 {
                return Err(Error::IO(io::Error::last_os_error()));
            } else {
                return Ok(bt);
            }
        }
    }
    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
    {
        let start = kstat::boot_time()?;
        let now = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
        let now = now.as_secs();
        if now < start {
            return Err(Error::General("time went backwards".into()));
        }
        bt.tv_sec = (now - start) as i64;
	    return Ok(bt);
    }

    #[warn(unreachable_code)]
    Err(Error::UnsupportedSystem)
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    pub fn test_os_type() {
        let typ = os_type().unwrap();
        assert!(typ.len() > 0);
        println!("os_type(): {}", typ);
    }

    #[test]
    pub fn test_os_release() {
        let release = os_release().unwrap();
        assert!(release.len() > 0);
        println!("os_release(): {}", release);
    }

    #[test]
    pub fn test_cpu_num() {
        let num = cpu_num().unwrap();
        assert!(num > 0);
        println!("cpu_num(): {}", num);
    }

    #[test]
    #[cfg(not(all(target_vendor = "apple", target_arch = "aarch64")))]
    pub fn test_cpu_speed() {
        let speed = cpu_speed().unwrap();
        assert!(speed > 0);
        println!("cpu_speed(): {}", speed);
    }

    #[test]
    pub fn test_loadavg() {
        let load = loadavg().unwrap();
        println!("loadavg(): {:?}", load);
    }

    #[test]
    pub fn test_proc_total() {
        let procs = proc_total().unwrap();
        assert!(procs > 0);
        println!("proc_total(): {}", procs);
    }

    #[test]
    pub fn test_mem_info() {
        let mem = mem_info().unwrap();
        assert!(mem.total > 0);
        println!("mem_info(): {:?}", mem);
    }

    #[test]
    #[cfg(not(any(target_os = "solaris", target_os = "illumos")))]
    pub fn test_disk_info() {
        let info = disk_info().unwrap();
        println!("disk_info(): {:?}", info);
    }

    #[test]
    pub fn test_hostname() {
        let host = hostname().unwrap();
        assert!(host.len() > 0);
        println!("hostname(): {}", host);
    }

    #[test]
    #[cfg(not(windows))]
    pub fn test_boottime() {
        let bt = boottime().unwrap();
        println!("boottime(): {} {}", bt.tv_sec, bt.tv_usec);
        assert!(bt.tv_sec > 0 || bt.tv_usec > 0);
    }

    #[test]
    #[cfg(target_os = "linux")]
    pub fn test_linux_os_release() {
        let os_release = linux_os_release().unwrap();
        println!("linux_os_release(): {:?}", os_release.name)
    }
}