#!/usr/bin/perl

#------ ----- ---- --- -- -  -   -    -     -
# This is rpmdepend version 0.0.1
# 
# RPMDEPEND is a program that goes through your
# currently installed RPM packages and finds out
# which dependencies are met and which aren't.
# it then generates a report of its findings.
#
# Often a newly installed RPM based system will
# be missing a few dependencies.  Some are
# necessary for the operation of certain packages
# some are really just suggestions (like csh...)
# (or aalib for gimp)
# 
# It is up to the sysadmin to make decisions
# (such as installing packages) based on the
# findings.
#
# Currently RPMDEPEND is a rapid prototype
# a true version would be a binary which can
# directly access the rpm database without
# calling on 'rpm' directly.  Due to its current
# implementation it churns your drive, forks
# often to 'sh' and 'rpm', and uses memory in
# bursts.
# 
# By releasing early the author hopes to recieve
# feed back as to usability features that may be
# desired; such as command line options for
# searching through some packages only, for
# using a criteria to install dependencies, and
# for alternate output modes or additional
# output information.
# 
# please contact the author (Daniel Lamblin) at:
# daniell@kapowee.com
# and begin your subject line with "rpmdepend"
# in case of difficulties try: daniell@slithy.toves.net
# 
# Currently ascii (stdout) output is formatted
# as:
# [blank line]
# PACKAGE:
# [package name]
# > Provides:
#   - [provided feature]
#   - [...]
# > Requires:
#   - [file name]	-- File Exists
#   - [package or lib]	-- provided by: [providing package]
#   ? [package] [<= || >=] [version string] -- check vers: [providing package]
#   ! [un-met req]	-- (not installed)
#   #PARSE!# [req]
#
# You probably won't get #PARSE!# problems... report them if you do
# You should manually check the version numbers of '?' lines (for now)
# You want to be aware of all '!' lines
#-     -    -   -  - -- --- ---- ----- ------


#--figure out user's command line options
#
for( $i=0; $i<@ARGV; $i++ ){
  
  #--check for "--help" and stop
  #
  if ($ARGV[$i] eq "--help"){
    print "\n";
    print "Command line arguments for $0 [rpmdepend.pl] are:\n";
    print " $0 [--help] [--grep regex | --package name]\n";
    print " --help         Show this help comment\n";
    print " --grep regex   Grep all packages for regex pattern match\n";
    print " --package name Only process named package\n";
    print "\n";
    exit 0;
  }
  
  #--check for "--grep" and its follow up argument
  #
  elsif ($ARGV[$i] eq "--grep"){
    #--if $exclude_grep_package has been defined or there is no argument
    #
    if (defined $exclude_grep_package || !defined $ARGV[i+1]){
      print "\nSee: \n$0 --help\n\n";
      exit 1;
    } else {
      $options = "-a |grep '$ARGV[$i+1]'";
      $exclude_grep_package = 1;
    }
  }
  
  #--check for "--package" and its follow up argument
  #
  elsif ($ARGV[$i] eq "--package"){
    #--if $exclude_grep_package has been defined or there is no argument
    #
    if (defined $exclude_grep_package || !defined $ARGV[i+1]){
      print "\nSee: \n$0 --help\n\n";
      exit 1;
    } else {
      $options = $ARGV[$i+1];
      $exclude_grep_package = 1;
    }
  }
}

#--if no options were used default query all
#
if (!defined $options) {$options = "-a";}    

#--once per text line from rpm query (and add options)
#
foreach $rpmpkg (`rpm -q $options`) {

  chomp ($rpmpkg);
  print "\nPACKAGE:\n$rpmpkg\n";
  print "> Provides:\n";

  #--once for each item the package provides
  #
  foreach $provide (`rpm -q --provides $rpmpkg`){

    chomp ($provide);
    #--(usually there's 2 spaces at the end): chop ($provide);chop ($provide);
    #--not always though, so lets remove all trailing whitespace
    #
    $provide =~ s/\s*$//;	#\s=whitespace *=any amount $=end of line
    print "  - $provide\n";
  }

  print "> Requires:\n";

  #--once for each item the package requires
  #
  foreach $require (`rpm -q -R $rpmpkg 2>&1`){

    chomp ($require);
    
    #--(usually there's 2 spaces at the end): chop ($require);chop ($require);
    #--not always though, so lets remove all trailing whitespace
    #
    $require =~ s/\s*$//;	#\s=whitespace *=any amount $=end of line
    
    #--sometimes there's a [worthless?] parenthetical note at the end
    #--lets chop it off too.
    #
    $require =~ s/\(.*?\)$//;	#\( and \)=a true paren char .*?=greedy [short] match of anything

    #--if there's an equal clause in $require, only use the first word
    #
    if ($require =~ '=') {
      ($first, $trash) = split(/.=/, $require, 2);	#.= matches both >= and <=;

      #--provider is what provides the requirement
      #--package could be a full package name
      #
      $package = `rpm -q $first 2>&1`;
      $provider = `rpm -q --whatprovides $first 2>&1`;
    } else {
      $package  = `rpm -q $require 2>&1`;
      $provider = `rpm -q --whatprovides $require 2>&1`;
    }

    #--if $require starts with a / and is a file on the filesystem
    #
    if ((substr($require, 0, 1) eq "/") && -e $require) {
      printf "  - %-32s -- File Exists\n", $require;
      
    #--if $require is a package name which is installed
    #
    } elsif ($package ne "package $require is not installed\n" && $package ne "") {
      if ($require =~ '=') {
        printf "  ? %-32s -- check vers:  $package", $require;
      } else {
        printf "  - %-32s -- provided by: $package", $require;
      }

    #--if $require is not provided by a package
    #
    } elsif ($provider eq "no package provides $require\n") {
      printf "  ! %-32s -- (not installed)\n", $require;

    #--if $require was a garbled thing that caused errors
    #
    } elsif ($provider eq "") {
      #--this means we needed to properly filter out parenthesis after $require
      print "  #PARSE!# $require\n";
    } else {
      printf "  - %-32s -- provided by: $provider", $require;
    }
  }
}