Command Line
How to Use curl to Download Files and Test URLs Step by Step
Use the curl command to download files, follow redirects, send headers and data, show response codes and timing, and fail properly in scripts.
6 min read
Topic
Network
SSH, curl, DNS, ports and HTTP APIs from the terminal, for when a connection or a request will not behave.
Command Line
How to Use scp and sftp to Transfer Files With Real Output
Use scp and sftp to copy files over SSH, with ports, keys and recursive copies, learn how scp changed in OpenSSH 9, and when to use rsync instead.
6 min read
Network
API Error 502 and 504 From Scripts and Proxies Fully
Understand API 502 Bad Gateway and 504 Gateway Timeout from scripts and proxies: where they come from, what to check upstream, and safe retries.
7 min read
Network
API Error 429 Too Many Requests and Backoff in Scripts
Handle API 429 Too Many Requests in scripts: read Retry-After and rate limit headers, exponential backoff with jitter, curl retries, throttling and batching.
6 min read
Command Line
How to Use VS Code Remote SSH and Dev Containers Properly
Use VS Code Remote SSH and Dev Containers: connect with your ssh config, devcontainer.json, features, ports and the problems to expect.
6 min read
Command Line
How to Set Up a Remote Dev Machine and Edit Over SSH
Set up a remote dev machine and edit over SSH: host config, connection reuse, tmux, port forwarding, editors over SSH and file sync.
6 min read
Databases
How to Use jq to Prepare JSON for Database Import Safely
Prepare JSON for a database import with jq: flatten to CSV or JSON Lines, handle nulls and types, escape safely, and load with COPY, mongoimport or SQLite.
6 min read
Performance
How to Avoid Repeated API Calls in Scripts With Real Output
Avoid repeated API calls in scripts: fetch once, pass data along, conditional requests with ETags, batching, pagination limits and a request counter.
6 min read
Network
SSH No Matching Host Key Type Found With Every Cause
Fix SSH no matching host key type found: why SHA-1 ssh-rsa was disabled, reading the server offer, HostKeyAlgorithms overrides, and re-keying.
6 min read
Network
SSH No Matching Key Exchange Method Found Causes and Fixes
Fix SSH no matching key exchange method found: read the server offer, old server versus new client, safe KexAlgorithms overrides and upgrades.
6 min read
Network
SSH Unprotected Private Key File Warning and How to Fix It
Fix the SSH unprotected private key file warning: set mode 600, fix ownership, handle WSL and Windows mounts, and see why open keys are refused.
6 min read
Network
SSH Host Key Verification Failed Explained With Every Cause
Understand SSH Host key verification failed: every cause, from a changed key or unwritable known_hosts to a non-interactive session, with the fix for each.
6 min read
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