Bash
PHP String Functions in Bash: A Cheat Sheet
The index to the Bash function library: every PHP string function with its pure-Bash equivalent, short tested snippets, and when to use awk or sed instead.
Category
Bash
The pure Bash function library (PHP-style helpers written in Bash) and practical shell scripting techniques.
Bash
Custom Bash Builtins in C: Lessons From awie-bash
Writing Bash builtins in C: the .def format, compiling into bash vs enable -f, what my old awie-bash code got wrong, and a tested loadable port with timings.
Bash
Bash trap: Clean Up Temp Files and Locks on Exit
Temp files and stale locks left behind by failed scripts are avoidable. Tested trap patterns for EXIT, INT, TERM and ERR, plus mkdir and flock locks.
Bash
getopts in Bash: Parse Command-Line Options Properly
A tested getopts skeleton for Bash scripts: flags, options with values, required options, error handling, and a manual loop for --long options.
Bash
Bash Strict Mode: What set -euo pipefail Really Does
set -euo pipefail is good advice, but each option has rules about when it fires. Here is what each one does and the cases that surprise people.
Bash
Read a File Line by Line in Bash (the Right Way)
while IFS= read -r line is the correct loop, but the last line, pipes, commands that read stdin and Windows line endings each have a trap. Here they are, tested.
Bash
str_pad() in Bash: Pad a String to a Fixed Length
PHP-compatible str_pad() in pure Bash, when printf "%-10s" and %05d are enough, and why multibyte text breaks the alignment of your columns.
Bash
in_array() in Bash: Check if an Array Contains a Value
A correct in_array() for Bash, an associative-array set for many lookups, and a demonstration of why [[ "${arr[*]}" =~ value ]] gives false positives.
Bash
explode() and implode() in Bash: Split and Join Strings
PHP's explode() and implode() in Bash: read -ra and mapfile -d for splitting, "${arr[*]}" for joining, and functions that cope with multi-character delimiters.
Bash
str_replace() in Bash: Replace Text in a String
Replace text in a Bash string without sed: ${s//search/replace}, anchored replacements, why you must quote the search, and what Bash 5.2 did to &.