tklauser / go-sysconf

sysconf for Go, without using cgo

go-sysconf

sysconf for Go, without using cgo or external binaries (e.g. getconf).

Supported operating systems: Linux, macOS, DragonflyBSD, FreeBSD, NetBSD, OpenBSD, Solaris/Illumos.

All POSIX.1 and POSIX.2 variables are supported, see References for a complete list.

Additionally, the following non-standard variables are supported on some operating systems:

Variable	Supported on
SC_PHYS_PAGES	Linux, macOS, FreeBSD, NetBSD, OpenBSD, Solaris/Illumos
SC_AVPHYS_PAGES	Linux, OpenBSD, Solaris/Illumos
SC_NPROCESSORS_CONF	Linux, macOS, FreeBSD, NetBSD, OpenBSD, Solaris/Illumos
SC_NPROCESSORS_ONLN	Linux, macOS, FreeBSD, NetBSD, OpenBSD, Solaris/Illumos
SC_UIO_MAXIOV	Linux

Usage

package main

import (
	"fmt"

	"github.com/tklauser/go-sysconf"
)

func main() {
	// get clock ticks, this will return the same as C.sysconf(C._SC_CLK_TCK)
	clktck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
	if err == nil {
		fmt.Printf("SC_CLK_TCK: %v\n", clktck)
	}
}

References

• POSIX documenation for sysconf
• Linux manpage for sysconf(3)
• glibc constants for sysconf parameters

go-sysconf's Issues

sysconf_values_linux_riscv64.go:7:24: _AIO_PRIO_DELTA_MAX redeclared in this block

By trying to build https://github.com/shirou/gopsutil which uses go-sysconf as a dependency I keep getting this error, not sure if it's gopsutil's author mistake or if something is broken over here, just to let you know.

# github.com/tklauser/go-sysconf
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:7:24: _AIO_PRIO_DELTA_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:7:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:8:24: _BC_BASE_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:8:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:9:24: _BC_DIM_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:9:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:10:24: _BC_SCALE_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:10:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:11:24: _BC_STRING_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:11:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:12:24: _COLL_WEIGHTS_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:12:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:13:24: _DELAYTIMER_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:13:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:14:24: _EXPR_NEST_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:14:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:15:24: _HOST_NAME_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:15:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:16:24: _LINE_MAX redeclared in this block
	previous declaration at ../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_amd64.go:16:24
../../../go/src/github.com/tklauser/go-sysconf/zsysconf_values_linux_riscv64.go:16:24: too many errors

openbsd/i386 build fails

The problem is with golang 1.16.6 symbol unix.RLIMIT_NPROC undefined on openbsd/i386 (all fine on openbsd/amd64):
https://github.com/tklauser/go-sysconf/blob/v0.3.6/sysconf_openbsd.go#L22

From the build log (https://github.com/rclone/rclone/runs/3150179581?check_suite_focus=true#step:15:35), section "compile all architectures test":

2021/07/24 10:53:13 Failed to run [go build --ldflags -s -X github.com/rclone/rclone/fs.Version=v1.56.0-beta.5602.1fcdec087.merge -trimpath -o rclone-v1.56.0-beta.5602.1fcdec087.merge-openbsd-386/rclone -tags  ..]: exit status 2
2021/07/24 10:53:13 Command output was:
# github.com/tklauser/go-sysconf
Error: ../../../../go/pkg/mod/github.com/tklauser/[email protected]/sysconf_openbsd.go:22:28: undefined: unix.RLIMIT_NPROC

rclone/rclone#5402 is pending on this issue.

Build fails on 32bit arch.

[email protected]/sysconf_linux.go:95:23: cannot use si.Totalram (type uint32) as type uint64 in argument to getMemPages
[email protected]/sysconf_linux.go:104:23: cannot use si.Freeram (type uint32) as type uint64 in argument to getMemPages

TestGetconf fails with OPEN_MAX

--- FAIL: TestGetconf (0.00s)
    sysconf_test.go:87: Sysconf(OPEN_MAX/4) returned 1048576, want 1024
FAIL

I think it's related to golang/go#46279

So my system OPEN_MAX is 1024, and Go just bumps it to 1024*1024. However getconf still reports the origin one.

`undefined: unix.ClockGetres`

Linux AMD64, go 1.17

github.com/tklauser/go-sysconf/sysconf_linux.go:133:12: undefined: unix.ClockGetres

golang.org/x/sys/unix/syscall_linux.go marked ClockGetres as Unimplemented

1489 /*
1490  * Unimplemented
1491  */
1492 // AfsSyscall
1493 // Alarm
1494 // ArchPrctl
1495 // Brk
1496 // Capget
1497 // Capset
1498 // ClockGetres

Trivial documentation bug in README.md

README.md has the following example:

func main() {
	// get clock ticks, this will return the same as C.sysconf(C._SC_CLK_TCK)
	clktck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
	if err != nil {
		fmt.Printf("SC_CLK_TCK: %v\n", clktck)
	}
}

I think the if block should execute if there is no error, i.e. if err == nil.

Currently the example is printing the value of clktck if an error occurred.