printf Command Cheat Sheet

printf formats and prints data. It is far more robust and portable than echo, especially for scripting.

Synopsis

printf FORMAT [ARGUMENT]...

Basic Usage

Unlike echo, printf does not automatically add a newline (\n). You must add it manually.

printf "Hello World\n"

format Strings

• %s: String
• %d: Integer
• %f: Float

printf "User: %s, ID: %d\n" "alice" 1001
# Output: User: alice, ID: 1001

Formatting Numbers

Precision (Floats)

Limit decimal places.

printf "Pi is approx %.2f\n" 3.14159
# Output: Pi is approx 3.14

Padding (Width)

Right-align numbers in a column of width 5.

printf "%5d\n" 10
printf "%5d\n" 200
# Output:
#    10
#   200

Leading Zeros

printf "%04d\n" 5
# Output: 0005

Formatting Columns (Tables)

Use negative width (%-10s) for left alignment.

printf "%-10s %-10s %s\n" "Name" "Role" "ID"
printf "%-10s %-10s %d\n" "Alice" "Admin" 101
printf "%-10s %-10s %d\n" "Bob" "User" 102

Name       Role       ID
Alice      Admin      101
Bob        User       102

Special Characters

• \n: Newline
• \t: Tab
• \\: Backslash
• \b: Backspace

printf "Column1\tColumn2\n"

Assign to Variable

Using command substitution.

MSG=$(printf "Error: File %s not found" "config.txt")
echo "$MSG"

Notes

• Portability: printf behaves consistently across different shells (bash, zsh, dash), whereas echo flags (like -e or -n) vary significantly. Always prefer printf for scripts.
• Arguments: If you provide more arguments than format specifiers, printf reuses the format string.

  printf "%s\n" A B C
  # Output:
  # A
  # B
  # C