OSX | Example of different commands displaying memory usage

osx.mem.inspections.sh

# Jaziel Lopez <juan.jaziel at gmail.com>
# Background:
# `free`is an utility command to display available memory in linux installation
#
# OSX does not ship `free` by default though alternatives exits.
# ==================================================================================
# Example of different commands displaying memory usage 
# 

> $ sysctl -a | grep hw\.mem | awk '{print "System Total Memory: " $2/1024/1024/1024 " Gb."}'
# System Total Memory: 16 Gb.

> $ memory_pressure
# The system has 2147483648 (524288 pages with a page size of 4096).

# Stats:
# Pages free: 93757
# Pages purgeable: 426583
# Pages purged: 100284

# Swap I/O:
# Swapins: 4394518
# Swapouts: 4562893

# Page Q counts:
# Pages active: 1962092
# Pages inactive: 1160853
# Pages speculative: 8825
# Pages throttled: 0
# Pages wired down: 671009

# Compressor Stats:
# Pages used by compressor: 295263
# Pages decompressed: 5027905
# Pages compressed: 6429165

# File I/O:
# Pageins: 3126315
# Pageouts: 7784

# System-wide memory free percentage: 76%

> $ vm_stat
# Mach Virtual Memory Statistics: (page size of 4096 bytes)
# Pages free:                               54315.
# Pages active:                           2061840.
# Pages inactive:                         1090096.
# Pages speculative:                        14180.
# Pages throttled:                              0.
# Pages wired down:                        677793.
# Pages purgeable:                         425760.
# "Translation faults":                  85656803.
# Pages copy-on-write:                    2792515.
# Pages zero filled:                     35527504.
# Pages reactivated:                       492638.
# Pages purged:                            100284.
# File-backed pages:                       446195.
# Anonymous pages:                        2719921.
# Pages stored in compressor:              930489.
# Pages occupied by compressor:            293880.
# Decompressions:                         5032910.
# Compressions:                           6429165.
# Pageins:                                3129691.
# Pageouts:                                  7784.
# Swapins:                                4394518.
# Swapouts:                               4562893.

> $ sysctl vm.swapusage
# vm.swapusage: total = 2048.00M  used = 542.25M  free = 1505.75M  (encrypted)