column [options] [file...]
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.
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.
The environment variable COLUMNS is used to determine the
size of the screen if no other information is available.
The column command appeared in 4.3BSD-Reno.
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.
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
The column command is part of the util-linux package and is
available from https://www.kernel.org/pub/linux/utils/util-linux/.