.\"	$NetBSD: rtbl.3,v 1.4 2017/01/28 21:31:50 christos Exp $
.\"
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.Dd June 26, 2004
.Dt RTBL 3
.Os
.Sh NAME
.Nm rtbl_create ,
.Nm rtbl_destroy ,
.Nm rtbl_set_flags ,
.Nm rtbl_get_flags ,
.Nm rtbl_set_prefix ,
.Nm rtbl_set_separator ,
.Nm rtbl_set_column_prefix ,
.Nm rtbl_set_column_affix_by_id ,
.Nm rtbl_add_column ,
.Nm rtbl_add_column_by_id ,
.Nm rtbl_add_column_entry ,
.Nm rtbl_add_column_entry_by_id ,
.Nm rtbl_new_row ,
.Nm rtbl_format
.Nd format data in simple tables
.Sh LIBRARY
The roken library (libroken, -lroken)
.Sh SYNOPSIS
.In rtbl.h
.Ft int
.Fn rtbl_add_column "rtbl_t table" "const char *column_name" "unsigned int flags"
.Ft int
.Fn rtbl_add_column_by_id "rtbl_t table" "unsigned int column_id" "const char *column_header" "unsigned int flags"
.Ft int
.Fn rtbl_add_column_entry "rtbl_t table" "const char *column_name" "const char *cell_entry"
.Ft int
.Fn rtbl_add_column_entry_by_id "rtbl_t table" "unsigned int column_id" "const char *cell_entry"
.Ft rtbl_t
.Fn rtbl_create "void"
.Ft void
.Fn rtbl_destroy "rtbl_t table"
.Ft int
.Fn rtbl_new_row "rtbl_t table"
.Ft int
.Fn rtbl_set_column_affix_by_id "rtbl_t table" "unsigned int column_id "const char *prefix" "const char *suffix"
.Ft int
.Fn rtbl_set_column_prefix "rtbl_t table" "const char *column_name" "const char *prefix"
.Ft "unsigned int"
.Fn rtbl_get_flags "rtbl_t table"
.Ft void
.Fn rtbl_set_flags "rtbl_t table" "unsigned int flags"
.Ft int
.Fn rtbl_set_prefix "rtbl_t table" "const char *prefix"
.Ft int
.Fn rtbl_set_separator "rtbl_t table" "const char *separator"
.Ft int
.Fn rtbl_format "rtbl_t table "FILE *file"
.Sh DESCRIPTION
This set of functions assemble a simple table consisting of rows and
columns, allowing it to be printed with certain options. Typical use
would be output from tools such as
.Xr ls 1
or
.Xr netstat 1 ,
where you have a fixed number of columns, but don't know the column
widths before hand.
.Pp
A table is created with
.Fn rtbl_create
and destroyed with
.Fn rtbl_destroy .
.Pp
Global flags on the table are set with
.Fa rtbl_set_flags
and retrieved with
.Fa rtbl_get_flags .
At present the only defined flag is
.Dv RTBL_HEADER_STYLE_NONE
which suppresses printing the header.
.Pp
Before adding data to the table, one or more columns need to be
created. This would normally be done with
.Fn rtbl_add_column_by_id ,
.Fa column_id
is any number of your choice (it's used only to identify columns),
.Fa column_header
is the header to print at the top of the column, and
.Fa flags
are flags specific to this column. Currently the only defined flag is
.Dv RTBL_ALIGN_RIGHT ,
aligning column entries to the right. Columns are printed in the order
they are added.
.Pp
There's also a way to add columns by column name with
.Fn rtbl_add_column ,
but this is less flexible (you need unique header names), and is
considered deprecated.
.Pp
To add data to a column you use
.Fn rtbl_add_column_entry_by_id ,
where the
.Fa column_id
is the same as when the column was added (adding data to a
non-existent column is undefined), and
.Fa cell_entry
is whatever string you wish to include in that cell. It should not
include newlines.
For columns added with
.Fn rtbl_add_column
you must use
.Fn rtbl_add_column_entry
instead.
.Pp
.Fn rtbl_new_row
fills all columns with blank entries until they all have the same
number of rows.
.Pp
Each column can have a separate prefix and suffix, set with
.Fa rtbl_set_column_affix_by_id ;
.Fa rtbl_set_column_prefix
allows setting the prefix only by column name. In addition to this,
columns may be separated by a string set with
.Fa rtbl_set_separator ( Ns
by default columns are not seprated by anything).
.Pp
The finished table is printed to
.Fa file
with
.Fa rtbl_format .
.Sh EXAMPLES
This program:
.Bd -literal -offset xxxx
#include <stdio.h>
#include <rtbl.h>
int
main(int argc, char **argv)
{
    rtbl_t table;
    table = rtbl_create();
    rtbl_set_separator(table, "  ");
    rtbl_add_column_by_id(table, 0, "Column A", 0);
    rtbl_add_column_by_id(table, 1, "Column B", RTBL_ALIGN_RIGHT);
    rtbl_add_column_by_id(table, 2, "Column C", 0);
    rtbl_add_column_entry_by_id(table, 0, "A-1");
    rtbl_add_column_entry_by_id(table, 0, "A-2");
    rtbl_add_column_entry_by_id(table, 0, "A-3");
    rtbl_add_column_entry_by_id(table, 1, "B-1");
    rtbl_add_column_entry_by_id(table, 2, "C-1");
    rtbl_add_column_entry_by_id(table, 2, "C-2");
    rtbl_add_column_entry_by_id(table, 1, "B-2");
    rtbl_add_column_entry_by_id(table, 1, "B-3");
    rtbl_add_column_entry_by_id(table, 2, "C-3");
    rtbl_add_column_entry_by_id(table, 0, "A-4");
    rtbl_new_row(table);
    rtbl_add_column_entry_by_id(table, 1, "B-4");
    rtbl_new_row(table);
    rtbl_add_column_entry_by_id(table, 2, "C-4");
    rtbl_new_row(table);
    rtbl_format(table, stdout);
    rtbl_destroy(table);
    return 0;
}
.Ed
.Pp
will output the following:
.Bd -literal -offset xxxx
Column A  Column B  Column C
A-1            B-1  C-1
A-2            B-2  C-2
A-3            B-3  C-3
A-4
               B-4
                    C-4
.Ed
.\" .Sh SEE ALSO