Shell script best practices

shell

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

wispbit

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Copy the rule

---

include: *.sh

---

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

Add the rule into your project

Save the copied content as: .wispbit/rules/shell-best-practices.md

Coderabbit

Install this rule for Coderabbit

Copy the configuration below and add it to your repository as .coderabbit.yml in your project root.

reviews:

  path_instructions:

    - path: "*.sh"

      instructions: |

        Follow these shell script best practices when writing or modifying bash scripts:

        1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

        Bad:

        ```bash

        #!/bin/bash

        echo "Hello World"

```

        Good:

        ```bash

        #!/usr/bin/env bash

        echo "Hello World"

```

        2. Use `${variable}` syntax for all variable references

        Bad:

        ```bash

        name="Alice"

        echo "Hello $name"

```

        Good:

        ```bash

        name="Alice"

        echo "Hello ${name}"

```

        3. Use double quotes around variable expansions to prevent word splitting and globbing

        Bad:

        ```bash

        files=$(ls)

        for file in $files; do

          rm $file

        done

```

        Good:

        ```bash

        files=$(ls)

        for file in "${files}"; do

          rm "${file}"

        done

```

        4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

        Bad:

        ```bash

        if [ -z "$input" ] || [ "$input" = "exit" ]; then

          echo "Exiting..."

          exit 0

fi

```

        Good:

        ```bash

        if [[ -z "${input}" || "${input}" = "exit" ]]; then

          echo "Exiting..."

          exit 0

fi

```

        5. Use `printf '%s\n'` instead of `echo` for output with special characters

        Bad:

        ```bash

        output="Text with special chars: * & $HOME"

        echo $output

```

        Good:

        ```bash

        output="Text with special chars: * & $HOME"

        printf '%s\n' "${output}"

```

        6. Use `readonly` for constants that should not be modified

        Bad:

        ```bash

        CONFIG_PATH="/etc/app/config.json"

        LOG_DIR="/var/log/app"

```

        Good:

        ```bash

        readonly CONFIG_PATH="/etc/app/config.json"

        readonly LOG_DIR="/var/log/app"

```

        7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

        Bad:

        ```bash

        sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

        Good:

        ```bash

        sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

Greptile

Install this rule for Greptile

Greptile rules can be added through the web interface. Please see this documentation for details on how to add custom rules and context.

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

File Path Patterns:

*.sh

Copilot

Install this rule for GitHub Copilot

Copilot instructions can be added through the interface. See the documentation for details on how to create coding guidelines.

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

File Path Patterns:

*.sh

Graphite Diamond

Install this rule for Graphite Diamond

Diamond custom rules can be added through the interface. See the documentation for details on how to create custom rules.

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

File Path Patterns:

*.sh

Cline

Use with Cline

Copy the rule below and ask Cline to review your code using this rule

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

OpenAI Codex

Use with OpenAI Codex

Copy the rule below and ask OpenAI Codex to review your code using this rule

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

Cursor

Use with Cursor

Copy the rule below and ask Cursor to review your code using this rule

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```

Claude Code

Use with Claude Code

Copy the rule below and ask Claude Code to review your code using this rule

Follow these shell script best practices when writing or modifying bash scripts:

1. Use `#!/usr/bin/env bash` instead of `#!/bin/bash` for better portability

Bad:

```bash

#!/bin/bash

echo "Hello World"

```

Good:

```bash

#!/usr/bin/env bash

echo "Hello World"

```

2. Use `${variable}` syntax for all variable references

Bad:

```bash

name="Alice"

echo "Hello $name"

```

Good:

```bash

name="Alice"

echo "Hello ${name}"

```

3. Use double quotes around variable expansions to prevent word splitting and globbing

Bad:

```bash

files=$(ls)

for file in $files; do

  rm $file

done

```

Good:

```bash

files=$(ls)

for file in "${files}"; do

  rm "${file}"

done

```

4. Use `[[` and `]]` instead of `[` and `]` for conditional expressions

Bad:

```bash

if [ -z "$input" ] || [ "$input" = "exit" ]; then

  echo "Exiting..."

  exit 0

fi

```

Good:

```bash

if [[ -z "${input}" || "${input}" = "exit" ]]; then

  echo "Exiting..."

  exit 0

fi

```

5. Use `printf '%s\n'` instead of `echo` for output with special characters

Bad:

```bash

output="Text with special chars: * & $HOME"

echo $output

```

Good:

```bash

output="Text with special chars: * & $HOME"

printf '%s\n' "${output}"

```

6. Use `readonly` for constants that should not be modified

Bad:

```bash

CONFIG_PATH="/etc/app/config.json"

LOG_DIR="/var/log/app"

```

Good:

```bash

readonly CONFIG_PATH="/etc/app/config.json"

readonly LOG_DIR="/var/log/app"

```

7. Use `|` as delimiter in `sed` commands when replacing paths containing slashes

Bad:

```bash

sed -i "s/${source_path}/${target_path}/" "${config_file}"

```

Good:

```bash

sed -i "s|${source_path}|${target_path}|" "${config_file}"

```