bash-optimize

CRITICAL GUIDELINES

Windows File Path Requirements

MANDATORY: Always Use Backslashes on Windows for File Paths

When using Edit or Write tools on Windows, you MUST use backslashes (\) in file paths, NOT forward slashes (/).

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Bash Script Optimizer

Purpose

Analyze and optimize bash scripts for maximum performance, reducing execution time and resource usage while maintaining correctness and readability.

Optimization Targets

Speed Optimization

• Reduce subshell spawning
• Replace external commands with bash builtins
• Optimize loop structures
• Implement parallel processing
• Use efficient I/O patterns

Memory Optimization

• Stream processing instead of loading files
• Efficient array usage
• Proper variable scoping
• Cleanup temporary data
• Avoid unnecessary string copies

Optimization Techniques

1. Subshell Elimination

Before:

# Spawns subshell for each
result=$(echo "$var" | tr 'a-z' 'A-Z')
count=$(cat file.txt | wc -l)
basename=$(basename "$path")

After:

# Pure bash - no subshells
result="${var^^}"
count=0; while IFS= read -r _; do ((count++)); done < file.txt
basename="${path##*/}"

2. External Command Replacement

External	Bash Equivalent
basename "$p"	"${p##*/}"
dirname "$p"	"${p%/*}"
echo "$s" | tr a-z A-Z	"${s^^}"
expr $a + $b	$((a + b))
cat file	< file or mapfile
cut -d: -f1	"${var%%:*}"
sed 's/a/b/g'	"${var//a/b}"

3. Loop Optimization

Before:

# Creates subshell, variables lost
cat file.txt | while read -r line; do
    ((count++))
done
echo "$count"  # Always 0!

After:

# No subshell, variables preserved
while IFS= read -r line; do
    ((count++))
done < file.txt
echo "$count"  # Correct value

4. Array vs String Processing

Before:

# Slow: string manipulation
files="file1.txt file2.txt file3.txt"
for f in $files; do
    process "$f"
done