column - Man Page
columnate lists
Examples (TL;DR)
- Format the output of a command for a 30 characters wide display:
printf "header1 header2\nbar foo\n" | column --output-width 30
- Split columns automatically and auto-align them in a tabular format:
printf "header1 header2\nbar foo\n" | column --table
- Specify the column delimiter character for the
--table
option (e.g. "," for CSV) (defaults to whitespace):printf "header1,header2\nbar,foo\n" | column --table --separator ,
- Fill rows before filling columns:
printf "header1\nbar\nfoobar\n" | column --output-width 30 --fillrows
Synopsis
column [options] [file ...]
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. The output is aligned to the terminal width in interactive mode and the 80 columns in non-interactive mode (see --output-width for more details).
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 a comma separated list of the column names as defined by --table-columns, or names defined by --table-column or it’s column number in order as specified by input. It’s possible to mix names and numbers. The special placeholder '0' (e.g. -R0) may be used to specify all columns and '-1' (e.g. -R -1) to specify the last visible column. It’s possible to use ranges like '1-5' when addressing columns by 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. The default is a terminal width and the 80 columns in non-interactive mode. The column headers are never truncated.
The placeholder "unlimited" (or 0) is possible to use to not restrict output width. This is recommended for example when output to the files rather than on terminal.
- -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.
- -C, --table-column properties
Define one column by comma separated list of column attributes. This option can be used more than once, every use defines just one column. The properties replace some of --table- options. For example --table-column name=FOO,right define one column where text is aligned to right. The option is mutually exclusive to --table-columns.
The currently supported attributes are:
- name=string
Specifies column name.
- trunc
The column text can be truncated when necessary. The same as --table-truncate.
- right
Right align text in the specified columns. The same as --table-right.
- width=number
Specifies column width. The width is used as a hint only. The width is strictly followed only when strictwidth attribute is used too.
- strictwidth
Strictly follow column width= setting.
- noextreme
Specify columns where is possible to ignore unusually long cells. See --table-noextreme for more details.
- wrap
Specify columns where is possible to use multi-line cell for long text when necessary. See --table-wrap.
- hide
Don’t print specified columns. See --table-hide.
- json=type
Define column type for JSON output, Supported are string, number and boolean.
- -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 argument. See also --table-column.
- -l, --table-columns-limit number
Specify maximal number of the input columns. The last column will contain all remaining line data if the limit is smaller than the number of the columns in the input data.
- -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".
- -m, --table-maxout
Fill all available space on output.
- -L, --keep-empty-lines
Preserve whitespace-only lines in the input. The default is ignore empty lines at all. This option’s original name was --table-empty-lines but is now deprecated because it gives the false impression that the option only applies to table mode.
- -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.
- -h, --help
Display help text and exit.
- -V, --version
Print version 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,FREQ,PASS --table-right FREQ,PASS
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
See Also
Reporting Bugs
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
Availability
The column command is part of the util-linux package which can be downloaded from Linux Kernel Archive.