beautify "apt list --upgradable" output

alu

#!/bin/bash

# beautify "apt list --upgradable" output

# sample output is like:

#    Listing... Done
#    bind9-dnsutils/stable-security 1:9.16.27-1~deb11u1 amd64 [upgradable from: 1:9.16.22-1~deb11u1]
#    bind9-host/stable-security 1:9.16.27-1~deb11u1 amd64 [upgradable from: 1:9.16.22-1~deb11u1]
#    bind9-libs/stable-security 1:9.16.27-1~deb11u1 amd64 [upgradable from: 1:9.16.22-1~deb11u1]
#    nodejs/unknown 16.14.2-deb-1nodesource1 amd64 [upgradable from: 16.14.1-deb-1nodesource1]


# beautified output will be like:

#    bind9-dnsutils : 1:9.16.22-1~deb11u1      ---> 1:9.16.27-1~deb11u1
#    bind9-libs     : 1:9.16.22-1~deb11u1      ---> 1:9.16.27-1~deb11u1
#    nodejs         : 16.14.1-deb-1nodesource1 ---> 16.14.2-deb-1nodesource1
#    bind9-host     : 1:9.16.22-1~deb11u1      ---> 1:9.16.27-1~deb11u1


# Similar output can be achived by:
#   apt list --upgradable 2>/dev/null | grep -v 'Listing' | column -t --table-hide 3


# The awk script calculates the width of the longest package name and the longest (existing) version name

apt list --upgradable 2>/dev/null | mawk -v FS="[/ \]]" -- '
        BEGIN{
            package_width=0; existing_version_width=0

            # these esc sequences work for 24 bit terminals. Use some other for 8 bit ones.
            package_color = "\033[38;2;234;143;255;1m"
            target_color  = "\033[38;2;143;220;255;1m"
            color_reset   = "\033[0m"
        }
        !/Listing/ {
            existing_versions[$1] = $7
            target_versions[$1]   = $3

            field_width = length($1)
            if( field_width > package_width )
                package_width = field_width
            field_width = length($7)
            if( field_width > existing_version_width )
                existing_version_width = field_width
        }
        END{
            for (package in existing_versions)
                printf("%s%*s:%s %-*s %s-> %s%s\n",
                       package_color, package_width, package, color_reset,
                       existing_version_width, existing_versions[package],
                       target_color, target_versions[package], color_reset)
        }
    '

A screenshot of this script, with the default color settings.