jeeves

perl learn perl by examples

#!/opt/bin/perl
process_args();
# Use "require" to allow process_args() to set @INC first
require 'TemplateParser.pm';

#-------------------------------------------------------------------------
# Translate the template file to an intermediate Perl file. Skip
# this step if the intermediate Perl file exists, and  is newer than 
# the template.
#-------------------------------------------------------------------------
my $compile_template = 0;
if (-e $inter_file) {
    if ((-M $inter_file) >= (-M $template_file)) {
        $compile_template = 1;
    }
} else {
    $compile_template = 1;
}
if ($compile_template) {
    if (TemplateParser->parse ($template_file, $inter_file) == 0) {
        print STDERR ("Translated $template_file to $inter_file\n") if $verbose;
    } else {
        die "Could not parse template file - exiting\n";
    }
}
#-------------------------------------------------------------------------
# Parse the input specification file
#-------------------------------------------------------------------------
require "${spec_parser}.pm"; $spec_parser->import;
$ROOT = $spec_parser->parse($spec_file);
print STDERR ("Parsed $spec_file\n") if $verbose;
$ROOT->print() if $debugging;
#-------------------------------------------------------------------------
# Eval the intermediate Perl file
#-------------------------------------------------------------------------
require $inter_file;
die "$@\n" if $@;
exit(0);

#----------------------------------------------------------------------------
sub process_args {
    $verbose = 1; $debugging = 0;
    $template_dir = $ENV{"JEEVESTEMPLATEDIR"};
    $template_file = "jeeves.template"; # default
    $spec_parser = "oo_schema";         # default
    if (exists ($ENV{"JEEVESOPTIONS"})) {
        print  "Using command line options from \"JEEVESOPTIONS\" \n";
        @ARGV = split (/\s/,$ENV{"JEEVESOPTIONS"});
    }
    while (@ARGV) {
        $a = shift @ARGV;
        if ($a eq "-h") {
            Usage();
        } elsif ($a eq "-s") {
            $spec_parser = shift @ARGV;
        } elsif ($a eq "-d") {
            $debugging = 1;
        } elsif ($a eq "-q") {
            $verbose = 0;
        } elsif ($a =~ /^-[Tt]$/) {
            $template_file = shift @ARGV ;
        } elsif ($a eq "-ti") {
            $inter_file = shift @ARGV ;
        } elsif ($a eq "-D") {
            my $code = shift @ARGV;    #-D foo=20 becomes ...
            eval("\$$code");           #eval ("$foo=20")
            die "Error in -D $code:\n$@\n" if $@;
        } else {
            $spec_file = $a;
        }
    }
    $template_found = 0;
    while (1) {
        if ($template_file && (-e $template_file)) {
            if (! $inter_file) {
                $inter_file = "$template_file.pl";
                $template_found = 1;
                last;
            }
        }
        if ($template_file !~ m'/') {
            $template_file = "$template_dir/$template_file";
        } else {
            last;
        }
    }
    if (! $template_found) {
        print STDERR "Please specify a template file\n";
        Usage();
    }
    if ((! $spec_file) || (! -e $spec_file)) {
        print STDERR "Please specify a valid specification file\n";
        Usage();
    }
    if (exists $ENV{"JEEVESLIBDIR"}) {
        push (@INC, split(/:/, $ENV{"JEEVESLIBDIR"}));
    }
}

#----------------------------------------------------------------------------
sub Usage {
    print STDERR <<"_EOT_";

Usage: jeeves <options> <specification file>
 where options are: 
 -t <template file>            : Name of the template file. 
                                 Default : "./jeeves.template"
                                 Default template directory = ".", which
                                 can be modified by setenv-ing
                                 "JEEVESTEMPLATEDIR"
 -q                            : Quiet Mode
 -d                            : Set a debugging trace. This is NOT quiet!
 -s <specification parser>     : Parser module that can parse the input
                                 specification file
                                 Default : "oo_schema"
[-ti <intermediate perl file>] : jeeves translates the template file to
                               : perl code. Default : "<template>.pl"
-D var[=value]                 : Define variables on the command line 

The command line can be specified in the envt. variable "JEEVESOPTIONS".

The pathname to all Jeeves modules can be set in the envt. variable 
    "JEEVESLIBDIR" (colon-separated);
_EOT_
    exit(1);
}