tablize

Introduction

The tablize utility can be used to pretty-print tables defined by the CSV format. It provides column alignments and visual decoration of the table both horizontally and vertically. To do so, a simple domain-specific language was introduced with its grammar described in the Decoration language section of this document.

Example

A simple table defining services and network ports for different hosts in the network:

$ cat config.csv
host,service,port
qa.example.com,apache,443
testing.example.com,apache,8080
*.example.com,apache,80

The above table can be rendered into the following text:

$ tablize config.csv -x 'union(outer, only(1))' -y all -a left,left,right
+---------------------+---------+------+
| host                | service | port |
+---------------------+---------+------+
| qa.example.com      | apache  |  443 |
| testing.example.com | apache  | 8080 |
| *.example.com       | apache  |   80 |
+---------------------+---------+------+

Build & install

There are two standard ways of obtaining the utility:

• by cloning the git repository: git clone https://github.com/lovasko/tablize
• by using the central Hackage server: cabal install tablize

Dependencies

The build process depends on the following packages from Hackage:

• base
• attoparsec
• comma
• optparse-applicative
• tabl
• text

Options

The command-line interface consists of an optional positional argument that specifies the input file (stdin is used if no file is specified) and three optional named parameters:

• -x|--horizontal HDECOR defines the horizontal decoration, using the custom DSL described below (default: union(outer, only(1)))

• -y|--vertical VDECOR defines the vertical decoration, using the custom DSL described below (default: all)

• -a|--alignment ALIGN defines the column alignment starting from the left-most column (default: empty string). Valid alignments are left, centre and right. Alignments are assigned starting from the left side, while all unspecified columns will default to left.

Decoration language

The decoration language is used to define the presence of decorative lines (separately for horizontal and vertical) within the table. Lines can be used to separate sections of the table - always the full length, row or column.

The decoration is represented by exactly one statement. All statements are described below:

The all statement results in all lines (in the relevant orientation) to be visible. Opposite effect can be achieved via the none statement that, naturally, makes no decorative lines visible.

The inner and outer statements, as the names suggest, provide means of decorating the inner and outer lines of the table respectively. These statements are best used when the number of columns or rows is not known beforehand.

The only statement expects a list of zero or more unsigned integer indices separated by the comma character(leftmost and topmost lines equal to zero) that should be contained in the decoration. An example of the statement is: only(1, 2, 3). The opposite statement, except, includes all but lines specified with indices.

Two combinators - union and isect can be used to specify a set union and set intersection of zero or more decorations separated by the comma character. The default value for the horizontal decoration is union(outer, only(1)), resulting in decoration seen in the Example section.

All whitespace is disregarded as non-relevant and can be used for stylistic purposes.

Examples

The following set of examples with operate on a simple 3x3 table filled with o characters:

$ cat o.csv
o,o,o
o,o,o
o,o,o

Inner lines only

$ tablize o.csv -x inner -y inner
o | o | o
--+---+--
o | o | o
--+---+--
o | o | o

Outer lines only

$ tablize o.csv -x outer -y outer
+-------+
| o o o |
| o o o |
| o o o |
+-------+

Separating the first column

$ tablize o.csv -x none -y 'only(1)'
o | o o
o | o o
o | o o

Default settings

$ tablize o.csv -x 'union(outer, only(1))' -y all
+---+---+---+
| o | o | o |
+---+---+---+
| o | o | o |
| o | o | o |
+---+---+---+

Separating all rows

$ tablize o.csv -x all -y none
-----
o o o
-----
o o o
-----
o o o
-----

License

The source code of the tablize utility is licensed under the terms of the 2-clause BSD license. Feel free to contact the author if you need a different license for your particular use-case.

Author

Daniel Lovasko [email protected]