cut

Documentation

Overview

Package cut implements the cut builtin command.

cut — remove sections from each line of files

Usage: cut OPTION... [FILE]...

Print selected parts of lines from each FILE to standard output. With no FILE, or when FILE is -, read standard input.

Exactly one of -b, -c, or -f must be specified.

Accepted flags:

-b LIST, --bytes=LIST
    Select only these bytes. LIST is a comma-separated set of byte
    positions and ranges (e.g. 1,3-5,7-). Positions are 1-based.

-c LIST, --characters=LIST
    Select only these characters (treated as bytes, matching GNU cut).
    Same list format as -b.

-d DELIM, --delimiter=DELIM
    Use DELIM instead of TAB for field delimiter. Used with -f.

-f LIST, --fields=LIST
    Select only these fields, separated by the delimiter character.
    Same list format as -b.

-n
    (ignored) Accepted for POSIX compatibility but has no effect,
    matching GNU coreutils behavior.

-s, --only-delimited
    Do not print lines not containing delimiters (only with -f).

--complement
    Complement the set of selected bytes, characters, or fields.

--output-delimiter=STRING
    Use STRING as the output delimiter. The default is the input
    delimiter.

--help
    Print this usage message to stdout and exit 0.

Exit codes:

0  All files processed successfully.
1  At least one error occurred (missing file, invalid argument, etc.).

Memory safety:

Lines are read via a streaming scanner with a per-line cap of
MaxLineBytes (1 MiB). Lines exceeding this cap produce an error
rather than an unbounded allocation. All loops check ctx.Err()
at each iteration to honour the shell's execution timeout.

Index

• Constants
• Variables

Constants

const MaxLineBytes = 1 << 20 // 1 MiB

MaxLineBytes is the per-line buffer cap for the line scanner.

Variables

var Cmd = builtins.Command{
	Name:        "cut",
	Description: "remove sections from each line",
	MakeFlags:   registerFlags,
}

Cmd is the cut builtin command descriptor.