Print out a terminfo entry including capname descriptions? - terminal

Question

What's the most straightforward way to print out a terminfo entry (e.g., for my current terminal: xterm-256color) that includes the short descriptions of each capname from the terminfo man page?
I know how to print out the terminfo entry for my terminal (with one capname per line) with:
infocmp -1
Generates:
# Reconstructed via infocmp from file: /usr/share/terminfo/78/xterm-256color
xterm-256color|xterm with 256 colors,
am,
bce,
ccc,
km,
mc5i
Etc.
And I can manually look up the descriptions of each capname in the terminfo man page (e.g., ccc represents "terminal can redefine existing colors"), but is there a way to display the descriptions for each capname without having to look each one up manually?
So, for example, I'd like to see something like this:
xterm-256color|xterm with 256 colors
am terminal has automatic margins
bce screen erased with background color
ccc terminal can redefine existing colors
km Has a meta key (i.e., sets 8th bit)
mc5i printer will not echo on screen
Etc.
The output from infocmp is consistently delimited and relatively easy to parse, but the tables listing the terminal capabilities on the terminfo man page, with varying column widths and capname descriptions that span multiple lines, are not. If they were, generating the output I describe would be more straightforward. Perhaps there's an alternative source for the content from the terminfo man page that's programmatically easier to manipulate?
I'm running GNU bash, version 4.4.23(1)-release (x86_64-apple-darwin18.0.0).

Answer 1

Probably not. Actually, the manual page and other files are constructed using scripts from a data file, but that is not installed.
Since it is generated, you could write a script to extract the information, though you'd find it challenging to do this as a bash script (perl yes, awk yes, sed...maybe). Here is a small chunk of the text (which is installed on your system):
.TS H
center expand;
c l l c
c l l c
lw25 lw6 lw2 lw20.
\fBVariable Cap- TCap Description\fR
\fBBooleans name Code\fR
auto_left_margin bw bw T{
cub1 wraps from column 0 to last column
T}
auto_right_margin am am T{
terminal has automatic margins
T}
back_color_erase bce ut T{
screen erased with background color
T}
can_change ccc cc
You can always list the long names using infocmp, and if the order were the same as for the (default) short names, you could combine those. But the listing for long-names is sorted alphabetically (in groups for boolean, numbers and strings, like the short names), while the short names are ordered by default to match the SVr4 terminfo data. You might see something like this:
xterm-256color|xterm with 256 colors
am auto_right_margin
bce back_color_erase
ccc backspaces_with_bs
km can_change
mc5i eat_newline_glitch
mir has_meta_key
msgr move_insert_mode
npc move_standout_mode
xenl no_pad_char
colors prtr_silent
cols columns
it init_tabs
lines lines
pairs max_colors
acsc max_pairs
bel acs_chars
blink back_tab
bold bell
Actually ncurses has an option allowing the names to be sorted, so that you could (almost) match the order of the right-column using the -sl option. You might see something like this:
xterm-256color|xterm with 256 colors
am auto_right_margin
bce back_color_erase
ccc backspaces_with_bs
xenl can_change
km eat_newline_glitch
mir has_meta_key
msgr move_insert_mode
npc move_standout_mode
mc5i no_pad_char
cols prtr_silent
it columns
lines init_tabs
colors lines
pairs max_colors
acsc max_pairs
cbt acs_chars
bel back_tab
cr bell
That's "almost", because the columns do not line up xenl with eat_newline_glitch because ncurses has an internal name for backspaces_with_bs which normally is not shown. With a change to the ncurses source to show that:
xterm-256color|xterm with 256 colors
am auto_right_margin
bce back_color_erase
OTbs backspaces_with_bs
ccc can_change
xenl eat_newline_glitch
Here's the perl script which I used to generate the examples:
#!/usr/bin/env perl
# $Id: infocmp2col,v 1.1 2018/12/20 22:35:57 tom Exp $
use strict;
use warnings;
sub infocmp($$) {
my $term = shift;
my $opts = shift;
my #data;
if ( open FP, "infocmp -1 $opts $term |" ) {
#data = <FP>;
close FP;
for my $n ( 0 .. $#data ) {
chomp $data[$n];
$data[$n] =~ s/,\s*$//;
$data[$n] =~ s/[#=].*//;
}
}
return \#data;
}
sub doit($) {
my $term = shift;
my #short_term = #{ &infocmp( $term, "-sl" ) };
my #long_term = #{ &infocmp( $term, "-L" ) };
for my $n ( 0 .. $#short_term ) {
if ( $short_term[$n] =~ /^\s/ ) {
printf "%s%s\n", $short_term[$n], $long_term[$n];
}
else {
printf "%s\n", $short_term[$n];
}
}
}
if ( $#ARGV >= 0 ) {
while ( $#ARGV >= 0 ) {
&doit( pop #ARGV );
}
}
else {
&doit( $ENV{TERM} );
}
1;
The minor fix that I mentioned is in ncurses 6.2 (see changes), so this "should work" for most users.