What Is The Equivalent of /Proc/Cpuinfo on Freebsd V8.1

What is the equivalent of /proc/cpuinfo on FreeBSD v8.1?

Use dmidecode command:

# dmidecode -t processor -t cache
# dmidecode 3.0
Scanning /dev/mem for entry point.
SMBIOS 2.4 present.

Handle 0x0004, DMI type 4, 35 bytes
Processor Information
        Socket Designation: LGA 775
        Type: Central Processor
        Family: Pentium 4
        Manufacturer: Intel
        ID: F6 06 00 00 FF FB EB BF
        Signature: Type 0, Family 6, Model 15, Stepping 6
        Flags:
                FPU (Floating-point unit on-chip)
                VME (Virtual mode extension)
                DE (Debugging extension)
                PSE (Page size extension)
                TSC (Time stamp counter)
                MSR (Model specific registers)
                PAE (Physical address extension)
                MCE (Machine check exception)
                CX8 (CMPXCHG8 instruction supported)
                APIC (On-chip APIC hardware supported)
                SEP (Fast system call)
                MTRR (Memory type range registers)
                PGE (Page global enable)
                MCA (Machine check architecture)
                CMOV (Conditional move instruction supported)
                PAT (Page attribute table)
                PSE-36 (36-bit page size extension)
                CLFSH (CLFLUSH instruction supported)
                DS (Debug store)
                ACPI (ACPI supported)
                MMX (MMX technology supported)
                FXSR (FXSAVE and FXSTOR instructions supported)
                SSE (Streaming SIMD extensions)
                SSE2 (Streaming SIMD extensions 2)
                SS (Self-snoop)
                HTT (Multi-threading)
                TM (Thermal monitor supported)
                PBE (Pending break enabled)
        Version: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
        Voltage: 1.4 V
        External Clock: 266 MHz
        Max Speed: 3800 MHz
        Current Speed: 2394 MHz
        Status: Populated, Enabled
        Upgrade: Other
        L1 Cache Handle: 0x0005
        L2 Cache Handle: 0x0006
        L3 Cache Handle: 0x0007
        Serial Number: To Be Filled By O.E.M.
        Asset Tag: To Be Filled By O.E.M.
        Part Number: To Be Filled By O.E.M.

Handle 0x0005, DMI type 7, 19 bytes
Cache Information
        Socket Designation: L1-Cache
        Configuration: Enabled, Not Socketed, Level 1
        Operational Mode: Write Back
        Location: Internal
......

What is equivalent of Linux's 'free' command on FreeBSD v8.1

vmstat has default output which is similar in nature and takes many options that give extremely detailed information, eg vmstat -m
swapinfo would cover the swap part
top -d1 causes top to print one screen and exit, and the banner is very similar to free. Use top -d1 | head -n 7 to see only the banner

What sample based profiling tool for FreeBSD?

The equivalent of oprofile on FreeBSD is hwpmc. It can do both system and process profiling; as of FreeBSD 7.2 it has callchain capture. There's lots of information about it at http://wiki.freebsd.org/PmcTools and the pmcstat man page contains instructions for profiling applications too.

Reading the route table on FreeBSD

This is documented in the man page route(4). Basically, you read() and write() a PF_ROUTE socket. You can look at the /sbin/route source for an example.

could not find /proc/self/maps

AFAIK, procfs isn't mounted by default in FreeBSD, so you should do it by yourself. Type as root:

mount -t procfs proc /proc

Or even better: add to /etc/fstab:

proc /proc procfs rw 0 0

Shell script: Portable way to programmably obtain the CPU vendor on POSIX systems

POSIX (IEEE Std 1003.1-2017) does not mandate a system utility or shell variable holding the CPU brand. The closest you'll get is uname -m, which is the "hardware type on which the system is running". Unfortunately, that command doesn't have standardized output, so while you might get amd64 on some older machines, you'll mostly get i686 or x86_64 these days.

POSIX does mandate c99, a basic C compiler interface, be present when a C compiler is available at all. You can use that to compile a naive version of cpuid:

$ cat cpuid.c 
#include <stdio.h>
#include <string.h>
#include <stdint.h>
int main() {
    uint32_t regs[4] = { 0 };
    char brand[13] = { 0 };
    #ifdef _WIN32
        __cpuidex((int *)regs, 0, 0);
    #else
        __asm volatile("cpuid" : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3]) : "a" (0), "c" (0));
    #endif
    memcpy(&brand[0], ®s[1], 4);
    memcpy(&brand[4], ®s[3], 4);
    memcpy(&brand[8], ®s[2], 4);
    printf("%s\n", brand);
    return 0;
}

On a variety of test machines, here's what I get:

$ c99 -o cpuid cpuid.c && ./cpuid # MacOS X
GenuineIntel
$ c99 -o cpuid cpuid.c && ./cpuid # Intel-based AWS EC2 (M5)
GenuineIntel
$ c99 -o cpuid cpuid.c && ./cpuid # AMD-based AWS EC2 (T3a)
AuthenticAMD

Wikipedia lists numerous other possible vendor brands based on the cpuid instruction, but the ones likely most interesting for your defined use case are:

GenuineIntel - Intel
AMDisbetter! - AMD
AuthenticAMD - AMD

Provided you had this simple executable available in your path, the POSIX-y logic would look like:

if cpuid | grep -q AMD; then
    : # AMD logic here
elif cpuid | grep -q Intel; then
    : # Intel logic here
else # neither Intel nor AMD
    echo "Unsupported CPU vendor: $(cpuid)" >&2
fi

If you have a very, very old multi-core motherboard from the days when AMD was pin-equivalent with Intel, then you might care to know if CPU0 and CPU1 are the same vendor, in which case the C program above can be modified in the assembly lines to check processor 1 instead of 0 (the second argument to the respective asm functions).

This illustrates one particular benefit of this approach: if what you really want to know is whether the CPU supports a particular feature set (and are just using vendor as a proxy), then you can modify the C code to check whether the CPU feature is actually available. That's a quick modification to the EAX value given to the assembly code and a change to the interpretation of the E{B,C,D}X result registers.

With regards to the availability of c99, note that:

A POSIX conforming system without c99 is proof that no C compiler's available on that system. If your target systems do not have c99, then you need to select and install a C compiler (gcc, clang, msvc, etc.) or attempt a fallback detection with eg /proc/cpuinfo.
The standard declares that "Unlike all of the other non-OB-shaded utilities in this standard, a utility by this name probably will not appear in the next version of this standard. This utility's name is tied to the current revision of the ISO C standard at the time this standard is approved. Since the ISO C standard and this standard are maintained by different organizations on different schedules, we cannot predict what the compiler will be named in the next version of the standard." So you should consider compiling with something along the lines of ${C99:-c99} -o cpuid cpuid.c, which lets you flex as the binary name changes over time.

How do I monitor the computer's CPU, memory, and disk usage in Java?

Along the lines of what I mentioned in this post. I recommend you use the SIGAR API. I use the SIGAR API in one of my own applications and it is great. You'll find it is stable, well supported, and full of useful examples. It is open-source with a ~~GPL 2~~ Apache 2.0 license. Check it out. I have a feeling it will meet your needs.

Using Java and the Sigar API you can get Memory, CPU, Disk, Load-Average, Network Interface info and metrics, Process Table information, Route info, etc.

What Is The Equivalent of /Proc/Cpuinfo on Freebsd V8.1