Table of Contents

The mkdir command creates directories. It is used in scripts and interactive workflows to prepare folder structures for logs, outputs, builds, and deployment artifacts.

Overview

Use mkdir when you need to:

  • Create one or more directories
  • Create nested directory paths in a single command
  • Set directory permissions at creation time
  • Build predictable project or environment folder structures

Syntax

mkdir [options] directory...

Common forms:

# Create one directory
mkdir reports

# Create multiple directories
mkdir logs tmp cache

# Create nested path safely
mkdir -p logs/archive/2026

Common Options

Option Purpose Example
-p Create parent directories as needed; no error if directory exists mkdir -p app/data/cache
-m MODE Set directory permissions (mode) explicitly mkdir -m 750 secure
-v Verbose output for each created directory mkdir -pv out/reports/weekly

Behavior Notes

  • Without -p, parent directories must already exist.
  • Without -p, existing target directories cause an error.
  • New directory permissions are affected by the process umask unless -m is used.
  • mkdir creates directories only; it does not create files.

Permissions and umask

By default, permissions are derived from the requested mode and the active umask.

Examples:

# Create with explicit permissions
mkdir -m 700 private-data

# Check current umask value
umask

Typical secure patterns:

  • 700 for private directories
  • 750 for owner/group read-execute access

Examples

# Create a single directory
mkdir backup

# Create several directories at once
mkdir bin config data

# Create nested directory tree
mkdir -p var/log/myapp/archive

# Create directory with explicit mode
mkdir -m 755 public-assets

# Verbose nested creation
mkdir -pv build/output/release

# Brace expansion for multiple environment folders
mkdir -p environments/{dev,test,prod}/logs

# Create date-based folder
mkdir -p "backups/$(date +%F)"

Safe Usage Guidelines

  1. Use -p in scripts to avoid failures when parents are missing.
  2. Quote paths that may contain spaces.
  3. Use explicit -m for security-sensitive directories.
  4. Validate variables in scripts before path expansion.

Scripting Patterns

Idempotent setup:

mkdir -p ./artifacts ./artifacts/logs ./artifacts/reports

Create per-service directory structure:

for service in api worker web; do
  mkdir -p "services/$service"/{config,logs,tmp}
done

Portability Notes

  • -p and -m are widely available across GNU and BSD systems.
  • Brace expansion is a shell feature (Bash/Zsh), not a mkdir feature.
  • Permission semantics still depend on platform and filesystem.

Troubleshooting

mkdir: cannot create directory ... No such file or directory

Cause: Parent path does not exist and -p was not used.

Fix:

mkdir -p parent/child/grandchild

mkdir: cannot create directory ... File exists

Cause: Target directory already exists.

Fix:

  • Use -p for idempotent operations
  • Choose a different name when duplication is not intended

Permission denied

Cause: Missing write permission in parent directory.

Fixes:

  • Check ownership and permissions with ls -ld parent
  • Create the directory in a writable location
  • Use elevated privileges only when appropriate

Notes

mkdir is foundational for repeatable environment setup. Combining mkdir -p with predictable directory conventions improves script reliability.

For command details and implementation-specific behavior, run:

man mkdir
mkdir --help
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