o0-o

# ssh_key_create.sh
#
# parameter: user@host
# example: [email protected]

( # try ed25519
  ( ssh-keygen -t ed25519 -b 4096 -f "~/.ssh/$1" &&
    ssh-copy-id -i ~/.ssh/"$1" "$1"
  ) ||

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# bash_version.sh

( bash --version |
    grep --only-matching --max-count=1 "([0-9]*\.){2}[0-9]*" |
    head -n 1 #`head --lines=` isn't portable, so `-n` is used
    
) 2>/dev/null || 

exit 1 #failure

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# serial.sh

( # edgeos
  show version |
    grep "HW S/N:" ||

  # linux/bsd x86
  dmidecode --string system-serial-number || 
  
  # macos

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# cpu_threads.sh

( # linux
  getconf _NPROCESSORS_ONLN ||
  
  # bsd
  sysctl -n hw.ncpu
  
) 2>/dev/null ||

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# disks.sh

( # linux
  lsblk --all --noheadings --list --output NAME,TYPE |
    grep disk |
    sed 's/[[:space:]]disk//g' ||
  
  # bsd
  geom disk list |
    grep "Geom name: " |

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# cpu_aes.sh

( # linux
  lscpu |
    grep --quiet "aes" ||
    
  # bsd
  sysctl dev. |
    grep --quiet "aes" ||

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# host_name.sh

hostname 2>/dev/null ||

exit 1 #failure

exit 0 #success

o0-o

# mem.sh

( # linux
  grep "MemTotal" /proc/meminfo |
    awk '{ printf "%d\n", $2 * 1000 }' ||
    
  # bsd
  sysctl -n hw.realmem 2>/dev/null ||

  # macos

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# math_round.sh
#
# parameter: number (float)
# example: 3.14

( echo "$1" |
    awk '{
        x=$1
        ival = int(x)    # integer part, int() truncates
        # see if fractional part

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# net_ip4.sh

( # linux (NetworkManager)
  nmcli -terse -mode tabular -fields IP4.ADDRESS device show ||
  
  # linux (iproute2)
  ip -family inet -brief address |

  # linux/bsd
  ( ip address || ifconfig ) |