textcolumns

Overview ¶

Package textcolumns helps to output structs (and events of structs) using metadata from a `Columns` instance in a tabular way suitable for consoles or other frontends using fixed-width characters / fonts.

It can automatically size the output tables according to either screen size or content and provides some helpful tools to get a consistent output.

Initializing ¶

You can create a new formatter by calling

tc := textcolumns.NewFormatter(columnMap)

You can specify options by adding one or more of the WithX() functions to the initializer. The columns.ColumnMap can be obtained by calling columns.GetColumpMap on your `Column` instance.

Output ¶

After you have initialized the formatter, you can use

tc.FormatHeader()

to obtain the header line as string, which will look something like this:

NODE                PID COMM             NAME                                 TIME

You can also pass a filled struct to

tc.FormatEntry(&event)

to get a string like this:

Node1                 2 AAA                                                   12ns

Even simpler, use

tc.WriteTable(os.Stdout, entries)

to directly print the whole table:

NODE                PID COMM             NAME                                 TIME
----------------------------------------------------------------------------------
Node1                 2 AAA                                                   12ns
Node1                 1 AAA              Yay                           14.677772ms
Node1                 2 AnotherComm                                    24.645772ms
Node2                 4 BBB                                           3.462217772s
Node2                 3 BBB                                                  333ns

Custom Columns ¶

By default, Columns will show all fields that have a column tag without the `hide` attribute. Using

tc.SetShowColumns("node,time")

you can adjust the output to contain exactly the specified columns.