printf

Additional Notes

printf prints formatted text using a format string and arguments, much like the C printf function. Unlike echo, it does not add a newline unless you ask for one, which makes it predictable in scripts.

The first argument is the format; remaining arguments fill its placeholders in order.

Syntax

printf FORMAT [arguments ...]

Parameters

• FORMAT: The format string with literal text and placeholders.
• arguments: Values substituted into the placeholders.

Common Format Specifiers

• %s: String.
• %d, %i: Signed decimal integer.
• %u: Unsigned integer.
• %x, %X: Hexadecimal (lower/upper case).
• %f: Floating-point number.
• %c: A single character.
• %b: String that interprets backslash escapes.
• %%: A literal percent sign.

Common Escapes

• \n: Newline.
• \t: Tab.
• \\: Backslash.
• \": Double quote.

Examples

printf "Hello, %s\n" "$USER"

Greet the current user, ending with a newline.

printf "Zero-padded: %05d\n" 42

Print 00042 with a fixed width.

printf "Hex: %x\n" 255

Print ff in hexadecimal.

printf "Pi: %.2f\n" 3.14159

Print Pi: 3.14 with two decimals.

printf "%s: %s\n" name value

Print a simple key: value line.

printf "%.0f\n" "$((bytes / 1024))"

Print an integer division result without decimals.

Practical Notes

• printf does not append a newline; add \n when you need one.
• %b expands \n and \t inside the argument; %s does not.
• Use %05d or %8s for aligned, padded columns in scripts.
• It is generally safer than echo when the input may start with - or contain backslashes.