synthesys-lab/agentize/shell-script-review

if [ -f XXX ] then
   ...
fi

arr=(apple banana cherry)
echo ${arr[0]}  # apple
echo ${arr[1]}  # banana

arr=(apple banana cherry)
echo ${arr[1]}  # apple
echo ${arr[2]}  # banana

#!/bin/bash  # or #!/bin/zsh
[ -n "$ZSH_VERSION" ] && setopt KSH_ARRAYS
arr=(apple banana cherry)
echo ${arr[0]}  # apple in both

for item in "${arr[@]}"; do
    echo "$item"
done

for item in "$@"; do
    case $item in
        --option)
            option_value="$2"
            shift 2
            ;;
        *)
            positional_args+=("$item")
            shift
            ;;
    esac
done

echo "$0"              # /path/to/script.sh (or bash if sourced)
echo "${BASH_SOURCE[0]}"  # /path/to/script.sh (always reliable)

echo "$0"              # /path/to/script.sh (or function name if sourced!)
echo "${(%):-%x}"      # /path/to/script.sh (reliable)
# BASH_SOURCE doesn't exist in zsh

#!/bin/bash
# Get script path reliably in both shells
if [ -n "$BASH_SOURCE" ]; then
    SCRIPT_PATH="${BASH_SOURCE[0]}"
elif [ -n "$ZSH_VERSION" ]; then
    SCRIPT_PATH="${(%):-%x}"
else
    SCRIPT_PATH="$0"
fi
 
SCRIPT_DIR="$(dirname "$SCRIPT_PATH")"
echo "Script location: $SCRIPT_DIR"

var="one two three"
echo $var       # one two three (3 arguments, split!)
echo "$var"     # one two three (1 argument, safe)
 
for word in $var; do echo "$word"; done
# Outputs: one / two / three

var="one two three"
echo $var       # one two three (1 argument, NO split by default!)
echo "$var"     # one two three (1 argument)
 
for word in $var; do echo "$word"; done
# Outputs: one two three (as single item!)
 
 
# Need explicit splitting in zsh:
for word in ${=var}; do echo "$word"; done
# Outputs: one / two / three

#!/bin/bash
# Always quote variables for safety
var="one two three"
echo "$var"
 
# For intentional splitting, use arrays:
read -ra words <<< "$var"
for word in "${words[@]}"; do
    echo "$word"
done

# Recursive glob needs enabling
shopt -s globstar
echo **/*.txt
 
# No ** support without the option
echo *.txt  # Only current directory

# Recursive glob works by default
echo **/*.txt
 
# Advanced patterns
echo **/*.txt~*test*  # Exclude files with 'test'
echo *.txt(.)         # Only regular files

#!/bin/bash
# Option 1: Use find instead of globs
find . -name "*.txt" -type f
 
# Option 2: Enable globstar in bash, works in zsh by default
if [ -n "$BASH_VERSION" ]; then
    shopt -s globstar
fi
echo **/*.txt
 
# Option 3: Stick to simple globs
echo *.txt

# Indexed array
arr=(a b c)
echo ${arr[0]}  # a
 
# Associative array
declare -A map
map[key1]="value1"
map[key2]="value2"
echo ${map[key1]}  # value1

# Indexed array (1-based!)
arr=(a b c)
echo ${arr[1]}  # a
 
# Associative array (different syntax)
typeset -A map
map=(key1 value1 key2 value2)
# OR
map[key1]="value1"
echo ${map[key1]}  # value1

#!/bin/bash
# Force bash-compatible arrays in zsh
[ -n "$ZSH_VERSION" ] && setopt KSH_ARRAYS
 
# Now arrays work the same way
arr=(a b c)
echo ${arr[0]}  # a in both
 
# For associative arrays, use bash syntax
declare -A map 2>/dev/null || typeset -A map  # Works in both
map[key1]="value1"
echo ${map[key1]}
 
## PATH Variable

 
In zsh, `$path` is an array view of the PATH variable, which can lead to confusion.
In bash, `$path` is just a regular variable.
 
Solution: Always use `$PATH` for environment variable access, and avoid using `$path` as variable name!
 
## Key Recommendations
 
1. Use `#!/bin/bash` as shebang (more portable)
2. Add setopt KSH_ARRAYS at the top if you must support zsh
3. Always quote variables: `"$var"` not `$var`
4. Use `"${arr[@]}"` for array expansion
5. Use the script path template for reliable path detection
6. Use find instead of complex globs for portability
7. Avoid using `$path` as in zsh, it is different view of the sameting, `$PATH`