select portions of each line of a
cut utility selects portions of each
line (as specified by list) from each
file and writes them to the standard output. If no
file arguments are specified, or a file argument is a
single dash (‘-’),
cut reads from the
standard input. The items specified by list can be in
terms of column position or in terms of fields delimited by a special
character. Column and field numbering starts from 1; output is in the same
order as input, not in the order selected.
list is a comma or whitespace separated set of numbers and/or number ranges. Number ranges consist of a number, a dash (‘-’), and a second number which select the fields or columns from the first number to the second, inclusive. Numbers or number ranges may be preceded by a dash, which selects all fields or columns from 1 to the first number. Numbers or number ranges may be followed by a dash, which selects all fields or columns from the last number to the end of the line. Numbers and number ranges may be repeated, overlapping, and in any order. It is not an error to select fields or columns not present in the input line.
The options are as follows:
- The list specifies byte positions.
- The list specifies character positions.
- Use the first character of delim as the field delimiter character. The default is the ⟨TAB⟩ character.
- The list specifies fields, separated by the field delimiter character. The selected fields are output, separated by the field delimiter character.
- Do not split multi-byte characters. A character is written to standard output if and only if the byte position holding its last byte is selected.
- Suppresses lines with no field delimiter characters. Unless specified, lines with no delimiters are passed through unmodified.
- The character encoding locale(1). It decides which byte sequences form characters.
If unset or set to "C", "POSIX", or an unsupported
-cdoes the same as
-nhas no effect, and
-duses the first byte of delim.
cut utility exits 0 if all input files
are output successfully, and >0 if an error occurs.
Extract login names and shells from the system passwd(5) file as “name:shell” pairs:
$ cut -d : -f 1,7 /etc/passwd
Show the names and login times of logged in users:
$ who | cut -c 1-8,18-30
cut utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
cut command first appeared outside Bell
Labs in AT&T System III UNIX and has been
available since 4.3BSD-Reno.
The original Bell Labs version was written by Gottfried W. R. Luderer and the BSD version by Adam S. Moskowitz and Marciano Pitargue.