fold — Break lines into shorter lines

Format

fold [–bs] [–w width] [–width] [file…]

Description

fold reads the standard input (stdin) or each file, if you specify any. Each input line is broken into lines no longer than width characters. If you do not specify width on the command line, the default line length is 80. The output is sent to the standard output (stdout).

Options

–b: Specifies width in bytes rather than in column positions; that is, fold does not interpret tab, backspace, and carriage return characters. If the last byte specified by width is part of a double-byte character, fold does not break the character. Instead, the line is broken before the double-byte character.
–s: Breaks each line at the last blank within width column positions. If there is no blank that meets the requirement, fold breaks the line normally.
–w width: Specifies a maximum line length of width characters.
–width: Is identical in effect to –w width.

Localization

fold uses the following localization environment variables:

LANG
LC_ALL
LC_CTYPE
LC_MESSAGES
NLSPATH

See Localization for more information.

Exit values

0: Successful completion
1: Failure because the input file could not be opened
2: Invalid command-line option or a missing width argument

Portability

POSIX.2, 4.2BSD.

The –width option is an extension of the POSIX standard.