column(1) — Linux manual pages

Linux manual pages	Section 1

DESCRIPTION

The column utility formats its input into multiple columns. The util support three modes:

columns are filled before rows: This is the default mode (required by backward compatibility).
rows are filled before columns: This mode is enabled by option −x, −−fillrows
table: Determine the number of columns the input contains and create a table. This mode is enabled by option −t, −−table and columns formatting is possible to modify by −−table−* options. Use this mode if not sure.

Input is taken from file, or otherwise from standard input. Empty lines are ignored and all invalid multibyte sequences are encoded by \x<hex> convention.

OPTIONS

The argument columns for −−table−* options is comma separated list of the column names as defined by −−table−columns or it's column number in order as specified by input. It's possible to mix names and numbers.

−J, −−json

Use JSON output format to print the table, the option −−table−columns is required and the option −−table−name is recommended.

−c, −−output−width width

Output is formatted to a width specified as number of characters. The original name of this option is −−columns; this name is deprecated since v2.30. Note that input longer than width is not truncated by default.

−d, −−table−noheadings

Do not print header. This option allows the use of logical column names on the command line, but keeps the header hidden when printing the table.

−o, −−output−separator string

Specify the columns delimiter for table output (default is two spaces).

−s, −−separator separators

Specify the possible input item delimiters (default is whitespace).

−t, −−table

Determine the number of columns the input contains and create a table. Columns are delimited with whitespace, by default, or with the characters supplied using the −−output−separator option. Table output is useful for pretty-printing.

−N, −−table−columns names

Specify the columns names by comma separated list of names. The names are used for the table header or to address column in option arguments.

−R, −−table−right columns

Right align text in the specified columns.

−T, −−table−truncate columns

Specify columns where text can be truncated when necessary, otherwise very long table entries may be printed on multiple lines.

−E, −−table−noextreme columns

Specify columns where is possible to ignore unusually long (longer than average) cells when calculate column width. The option has impact to the width calculation and table formatting, but the printed text is not affected.

The option is used for the last visible column by default.

−e, −−table−header−repeat

Print header line for each page.

−W, −−table−wrap columns

Specify columns where is possible to use multi-line cell for long text when necessary.

−H, −−table−hide columns

Don't print specified columns. The special placeholder '−' may be used to hide all unnamed columns (see −−table-columns).

−O, −−table−order columns

Specify columns order on output.

−n, −−table−name name

Specify the table name used for JSON output. The default is "table".

−L, −−table−empty−lines

Insert empty line to the table for each empty line on input. The default is ignore empty lines at all.

−r, −−tree column

Specify column to use tree-like output. Note that the circular dependencies and other anomalies in child and parent relation are silently ignored.

−i, −−tree−id column

Specify column with line ID to create child-parent relation.

−p, −−tree−parent column

Specify column with parent ID to create child-parent relation.

−x, −−fillrows

Fill rows before filling columns.

−V, −−version

Display version information and exit.

−h, −−help

Display help text and exit.

ENVIRONMENT

The environment variable COLUMNS is used to determine the size of the screen if no other information is available.

HISTORY

The column command appeared in 4.3BSD-Reno.

BUGS

Version 2.23 changed the −s option to be non-greedy, for example:

printf "a:b:c\n1::3\n" | column −t −s ':'

Old output:

a  b  c
1  3

New output (since util-linux 2.23):

a  b  c
1     3

Historical versions of this tool indicated that "rows are filled before columns" by default, and that the −x option reverses this. This wording did not reflect the actual behavior, and it has since been corrected (see above). Other implementations of column may continue to use the older documentation, but the behavior should be identical in any case.

EXAMPLES

Print fstab with header line and align number to the right:

sed 's/#.*//' /etc/fstab | column −−table −−table-columns SOURCE,TARGET,TYPE,OPTIONS,PASS,FREQ −−table-right PASS,FREQ

Print fstab and hide unnamed columns:

sed 's/#.*//' /etc/fstab | column −−table −−table-columns SOURCE,TARGET,TYPE −−table-hide −

Print a tree:

echo −e '1 0 A\n2 1 AA\n3 1 AB\n4 2 AAA\n5 2 AAB' | column −−tree-id 1 −−tree-parent 2 −−tree 3
1  0  A
2  1  |-AA
4  2  | |-AAA
5  2  | `-AAB
3  1  `-AB

AVAILABILITY

The column command is part of the util-linux package and is available from https://www.kernel.org/pub/linux/utils/util-linux/.

  Copyright (c) 1989, 1990, 1993
The Regents of the University of California.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

    (#)column.1 8.1 (Berkeley) 6/6/93

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