Mac OS - command line hacks

processor bits

"processor bits" means that how much data a microprocessor will process within one instruction cycle i.e. fetch-decode-execute

32-bit means that a microprocessor can execute 4 bytes of data in one instruction cycle

while 64-bit means that a microprocessor executes can execute 8 bytes of data in one instruction cycle.

$ sysctl hw | grep cpu #sysctl hw.cpu64bit_capable
hw.ncpu: 8
hw.activecpu: 8
hw.physicalcpu: 4
hw.physicalcpu_max: 4
hw.logicalcpu: 8
hw.logicalcpu_max: 8
hw.cputype: 7
hw.cpusubtype: 8
hw.cpu64bit_capable: 1
hw.cpufamily: 280134364
hw.cpufrequency: 2800000000
hw.cpufrequency_min: 2800000000
hw.cpufrequency_max: 2800000000
hw.cputhreadtype: 1

$ getconf LONG_BIT
64

The number of bits in a processor refers to the size of the data types that it handles and the size of its registry. Simply put, a 64-bit processor is more capable than a 32-bit processor because it can handle more data at once.

CPU info

sysctl -n machdep.cpu.brand_string
Intel(R) Core(TM) i7-4980HQ CPU @ 2.80GHz

$ system_profiler | grep Processor
    Apple: AUDynamicsProcessor:
    Apple: AUVoiceProcessor:
      Processor Name: Intel Core i7
      Processor Speed: 2.8 GHz
      Number of Processors: 1
    <key>BootCampProcessorPstates</key>
    |         "BootCampProcessorPstates" = <0a00>

no of cores

$ sysctl -n hw.ncpu
8

IP address of Machine

$ ipconfig getifaddr en0
10.11.208.214

or

$ ifconfig | grep inet
inet6 ::1 prefixlen 128
inet 127.0.0.1 netmask 0xff000000
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
inet6 fe80::c6b3:1ff:fed3:d771%en0 prefixlen 64 scopeid 0x4
inet 10.11.208.214 netmask 0xfffffe00 broadcast 10.11.209.255
inet6 fe80::7023:7bff:fee3:61e2%awdl0 prefixlen 64 scopeid 0x9

Change password using DsCl (Directory Service CLI)

dscl . -passwd /Users/prayagupd
New Password: dreams
passwd: DS error: eDSAuthPasswordTooShort

<dscl_cmd> DS Error: -14170 (eDSAuthPasswordTooShort)

Note

$ man dscl | grep "passwd"

     Usage: passwd user_path [new_pasword | old_password new_pasword]

Uninstall application

mdfind -name "Skype"
/Applications/Skype.app

sudo rm -rf /Applications/Skype.app

add a printer (lpadmin)

find the IP address of the printer, and then add it to macos printers.

http://apple.stackexchange.com/q/126834/76240


printer stat

lpstat -p
printer _10_10_10_113 is idle.  enabled since Thu Oct 20 17:23:31 2016
 Waiting for printer to finish.
printer _10_20_50_100 is idle.  enabled since Fri Sep  9 15:39:45 2016

RAM Memory usage

$ vm_stat 
Mach Virtual Memory Statistics: (page size of 4096 bytes)
Pages free:                              264375.
Pages active:                           2027888.
Pages inactive:                          651659.
Pages speculative:                        23565.
Pages throttled:                              0.
Pages wired down:                        852647.
Pages purgeable:                          39328.
"Translation faults":                 880109291.
Pages copy-on-write:                   44871249.
Pages zero filled:                    433518664.
Pages reactivated:                      5346396.
Pages purged:                           1423915.
File-backed pages:                       379668.
Anonymous pages:                        2323444.
Pages stored in compressor:             2870604.
Pages occupied by compressor:            372004.
Decompressions:                        33640670.
Compressions:                          43459639.
Pageins:                               10427527.
Pageouts:                                 34549.
Swapins:                               32669611.
Swapouts:                              34330610.