Tags
#php
#kotlin
#bash
#go
#sql
#rust
#typescript
#html
#java
#python
#files
#utils
#strings
#http
#concurrency
#async
#json
#arrays
#security
#types
#crypto
#database
#dates
#format
Bash
URL-Encode and URL-Decode
Encode and decode URL-safe strings entirely in bash — no python or external tool required. Useful in pure-shell deployment scripts that need to build query strings.
@admin
Bash
Run on Multiple Hosts via SSH (with progress)
Iterate a host list, run the same command on each, show colored OK/FAIL summary at the end. Useful for ad-hoc fleet operations without setting up Ansible.
Bash
Hash File (SHA-256)
Compute and verify file checksums for downloads, backups, and integrity audits. sha256sum on Linux; shasum -a 256 on macOS.
Bash
Get Script's Own Directory
The "where am I" boilerplate that every nontrivial bash script needs. Resolves symlinks correctly with realpath, falls back gracefully if realpath is missing.
Bash
Default Value for Unset Variable
Three parameter-expansion idioms for "use this if the variable is empty / unset". Replaces the verbose `if [[ -z "$VAR" ]]; then VAR=default; fi` everywhere.
Bash
Substring + Find/Replace (parameter expansion)
Bash's ${var:offset:length} and ${var//pattern/replacement} let you do most string operations without ever spawning sed. Faster, and the syntax is portable across modern shells.
Bash
Uppercase / Lowercase / Title Case
Bash 4+ has built-in case conversion via parameter expansion. No need for `tr` or `awk` for most cases.
Bash
Download with Progress Bar
Show a progress bar for long downloads. wget gives a great built-in bar; curl needs an explicit flag.
Bash
Find + Replace Across Many Files
Use `find` + `sed -i` to do project-wide refactors. Always test the regex first with a dry run.
Bash
Extract JSON Field with jq
jq is the de-facto JSON tool. Pipe any JSON in, get a parsed/filtered/reshaped result out. Indispensable in deploy scripts that consume API output.
Bash
Pretty-Print JSON from cURL
Pipe API responses through jq for syntax-colored, indented output. Also great for extracting specific fields without writing a parser.
Bash
Add / Subtract Time from Date
GNU date accepts natural-language deltas: "+1 day", "-3 weeks", "now + 2 hours". Combine with -d to compute against any reference date.
Bash
Convert Between Timezones
Set TZ inline to print a date in a specific timezone, then read with another TZ. Avoids messing with the system timezone.
Bash
Days Between Two Dates
Convert both dates to epoch seconds, subtract, divide. Works for hours/minutes too with the obvious divisor.
Bash
Format Date Like a Pro
`date` accepts a format string + optional override of the date being formatted. The +%FT%TZ form gives you ISO-8601 / RFC-3339 in one call.
Bash
Progress Bar (basic)
Draw a single-line progress bar that updates in place. Useful for batch jobs where you know the total work count up front.
Bash
Tail Last N Lines (no `tail` shortcuts)
`tail -n 20` works for any case where tail is available. The pure-bash version below is useful inside containers or rescue shells where coreutils is missing.