albertywu

cheat sheet for https://tldp.org/LDP/abs/html/parameter-substitution.html

---

Variable existence checking

${var:?}          # returns exit-code 1 if var not defined or null
${var:?err_msg}   # prints err_msg and returns exit-code 1 if var not defined or null

albertywu

# note: run as root

devicemount=/mnt
logicalname=/dev/md0

# get instance storage block devices
devices=( $(lsblk -o name,type,size,model,mountpoint | grep -i "NVMe Instance Storage" | awk '{print "/dev/"$1}') )

if [[ "${#devices[@]}" -gt 0 ]] ; then
  mkdir -p "$devicemount"

albertywu

Convert table t1 of this form:

id | p50 | p75 | p95
---------------------
1  | 10  | 11  | 12
2  | 13  | 14  | 15

into this form:

albertywu

echo "console.log(require('v8').getHeapStatistics())" | node - | grep heap_size_limit

# both max-old-space-size and max_old_space_size work
export NODE_OPTIONS="--max-old-space-size=16384"
export NODE_OPTIONS="--max_old_space_size=16384"

# alternatively, "node --max-old-space-size=16384 ..."

albertywu

const o = { foo: 1, bar: 2 }
const a = [1, 2, 3]

// iterate over keys in object
for (prop of Object.keys(o)) {
  console.log(prop)
}

// iterate over values in object
for (value of Object.values(o)) {

albertywu

go install github.com/ankitpokhrel/jira-cli/cmd/jira@latest
export JIRA_API_TOKEN=$(usso -ussh t3 -print)
jira setup

# Add to startup script:
jira()
{
	unset -f jira
	JIRA_API_TOKEN=$(usso -ussh t3 -print)

albertywu

using latest version 0.9.0

1. works without cluster_id

resource "buildkite_pipeline" "wua-test-no-cluster" {
  name = "wua-testing-no-cluster"
  description = "testing creating a pipeline without cluster"
  repository = "gitolite@code.uber.internal:mobile/android"
  default_branch = "main"
  steps = file("./pipelines/mobile-release/metro-minion-build-release-apk-android.yml")

albertywu

# Usage:
# sqlcsv foo.csv foo 'select count(*) from foo;'
#
# Requirement:
# brew install sqlite

function sqlcsv {
  local file="$1"
  local table="$2"
  local cmd="$3"

albertywu

Stack overflow

albertywu

I want to create a python CLI tool called 'clibuddy' that uses the 'click' library.

The CLI tool will wrap another command, and will either 1) print out detailed information of what failed or 2) attempt to fix errors any time the wrapped command fails with exit code > 0.

Structure of CLI app:

clibuddy --tool="tools/mytool.py" --explain mytool ...mytool_args
clibuddy --tool="tools/mytool.py" --fix mytool ...mytool_args