Find all versions of a package that were available in a channel and the revision you can download it from using https://github.com/lazamar/nix-package-versions

nix-versions

#!/usr/bin/env bash

# Check if gum is installed
if ! command -v gum &>/dev/null; then
  echo "Error: gum is not installed. Please install it first."
  exit 1
fi

# Default values
CHANNEL="nixpkgs-unstable"
FORMAT=""

# Show help function
show_help() {
  echo "Usage: $0 [-c channel] [-f format] package" >&2
  echo >&2
  echo "Options:" >&2
  echo "  -h            Show this help message" >&2
  echo "  -c <channel>  Specify the Nix channel (default: nixpkgs-unstable)" >&2
  echo "  -f <format>   Output format (env|shell|profile|in-shell)" >&2
  echo >&2
  echo "Examples:" >&2
  echo "  $0 python                         # Search python in nixpkgs-unstable" >&2
  echo "  $0 -c nixos-23.05 python         # Search python in nixos-23.05" >&2
  echo "  $0 -f shell python               # Get nix shell command for python" >&2
  exit 1
}

# Parse command line arguments
while getopts "c:f:h" opt; do
  case $opt in
  c)
    CHANNEL="$OPTARG"
    ;;
  f)
    FORMAT="$OPTARG"
    ;;
  h)
    show_help
    ;;
  \?)
    echo "Invalid option: -$OPTARG" >&2
    show_help
    ;;
  esac
done

# Shift off the options and optional --
shift $((OPTIND - 1))

# Get package name from argument or gum input if in TTY
PACKAGE=${1}

if [ -z "$PACKAGE" ]; then
  if [ -t 0 ]; then # Check if running in a TTY
    PACKAGE=$(gum input --placeholder "Enter package name" --header "Which package do you want to search?")
  fi

  if [ -z "$PACKAGE" ]; then
    show_help
  fi
fi

URL="https://lazamar.co.uk/nix-versions/?channel=${CHANNEL}&package=${PACKAGE}"

# Fetch data
echo "Fetching data for package '${PACKAGE}' from channel '${CHANNEL}'..." >&2
HTML=$(curl -sL "$URL")

# Extract the table data
DATA=$(echo "$HTML" | grep -Eo '<tbody>.*</tbody>' || echo "")

if [ -z "$DATA" ]; then
  echo "Error: No data found for package '${PACKAGE}' in channel '${CHANNEL}'" >&2
  exit 1
fi

# Process the data into different formats
process_data() {
  echo "$DATA" | grep -o '<tr[^>]*>.*</tr>' | sed 's/<tr[^<]*>/\n/g' | while read -r line; do
    data=$(echo "$line" | grep -o '<td>[^<]*</td>' | sed 's/<td>\([^<]*\)<\/td>/\1/')
    package=$(echo "$data" | sed -n '1p')
    version=$(echo "$data" | sed -n '2p')
    revision=$(echo "$line" | grep -o '<a[^<]*</a>' | sed 's/<a[^>]*>\([^<]*\)<\/a>/\1/' | sed -n '1p')
    date=$(echo -n "$data" | sed -n '3p')

    if [ "$package" != "$PACKAGE" ]; then
      continue
    fi

    printf "%s %s %s\n" "$version" "$revision" "$date"
  done
}

# Build data array
DATA=$(process_data | sort -k3,3r -k1,1r)

# Let user filter the versions sorted by date and without the revision in the output
CHOICE=$(echo "$DATA" | gum filter --height=20 --reverse --header "Select version" || echo "")

if [ -z "$CHOICE" ]; then
  echo "Error: No version selected" >&2
  exit 1
fi

VERSION=$(echo "$CHOICE" | cut -d' ' -f1)
REVISION=$(echo "$CHOICE" | cut -d' ' -f2)

TEMPLATE_ENV=$(
  cat <<EOF
nix-env -iA $PACKAGE -f https://github.com/NixOS/nixpkgs/archive/$REVISION.tar.gz
EOF
)

TEMPLATE_IN_SHELL=$(
  cat <<EOF
nix-shell -p $PACKAGE -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/$REVISION.tar.gz
EOF
)

TEMPLATE_SHELL=$(
  cat <<EOF
nix shell github:nixos/nixpkgs/$REVISION#$PACKAGE
EOF
)

TEMPLATE_PROFILE=$(
  cat <<EOF
nix profile install nixpkgs/$REVISION#$PACKAGE
EOF
)

TEMPLATE=$(
  cat <<EOF
# Install $PACKAGE with nix-env.

\`\`\`sh
$TEMPLATE_ENV
\`\`\`

# Use $PACKAGE in a nix-shell.

\`\`\`sh
$TEMPLATE_IN_SHELL
\`\`\`

# Use $PACKAGE with nix shell.

\`\`\`sh
$TEMPLATE_SHELL
\`\`\`

# Install $PACKAGE with nix profile.

\`\`\`sh
$TEMPLATE_PROFILE
\`\`\`

# Use $PACKAGE in a nix script via tarball

\`\`\`nix
let
    pkgs = import (builtins.fetchTarball {
        url = "https://github.com/NixOS/nixpkgs/archive/$REVISION.tar.gz";
    }) {};

    myPkg = pkgs.$PACKAGE;
in
...
\`\`\`

# Use $PACKAGE in a nix script via Git

\`\`\`nix
let
     pkgs = import (builtins.fetchGit {
         # Descriptive name to make the store path easier to identify
         name = "my-old-revision";
         url = "https://github.com/NixOS/nixpkgs/";
         ref = "refs/heads/$CHANNEL";
         rev = "$REVISION";
     }) {};

     myPkg = pkgs.$PACKAGE;
in
...
\`\`\`
EOF
)
INFO="
For more information, see the [Installation Instructions](https://lazamar.co.uk/nix-versions/?package=$PACKAGE&version=$VERSION&fullName=$PACKAGE-$VERSION&keyName=$PACKAGE&revision=$REVISION&channel=$CHANNEL)
"

# Format the output if format is not specified
case "$FORMAT" in
'env')
  echo "$TEMPLATE_ENV"
  ;;
'shell')
  echo "$TEMPLATE_SHELL"
  ;;
'profile')
  echo "$TEMPLATE_PROFILE"
  ;;
'in-shell')
  echo "$TEMPLATE_IN_SHELL"
  ;;
*)
  gum format "$TEMPLATE$INFO"
  ;;
esac