Question

我无法获取下面的Perl脚本来写入文件output.html。

我还不需要成为CGI脚本，但这是最终目的。

任何人都可以告诉我为什么它没有写任何文本到output.html？

#!/usr/bin/perl

#-----------------------------------------------------------------------
# This script should work as a CGI script, if I get it correctly.
# Most CGI scripts for Perl begin with the same line and must be
# stored in your servers cgi-bin directory. (I think this is set by
# your web server.
#
# This scripts will scrape news sites for stories about topics input
# by the users.
#
# Lara Landis
# Sinister Porpoise Computing
# 1/4/2018
# Personal Perl Project
#-----------------------------------------------------------------------

@global_sites = ();

print( "Starting program.\n" );

if ( !( -e "sitedata.txt" ) ) {
    enter_site_info( @global_sites );
}

if ( !( -e "scrpdata.txt" ) ) {

    print( "scrpdata.txt does not exist. Creating file now.\n" );
    print( "Enter the search words you wish to search for below. Press Ctrl-D to finish.\n" );

    open( SCRAPEFILE, ">scrpdata.txt" );
    while ( $line = <STDIN> ) {
        chop( $line );
        print SCRAPEFILE ( "$line\n" );
    }
    close( SCRAPEFILE );
}

print( "Finished getting site data..." );
scrape_sites( @global_sites );

#----------------------------------------------------------------------
# This routine gets information from the user after the file has been
# created. It also has some basic checking to make sure that the lines
# fed to it are legimate domains.  This is not an exhaustive list of
# all domains in existence.
#----------------------------------------------------------------------
sub enter_site_info {
    my ( @sisites ) = @_;

    $x = 1;

    open( DATAFILE, ">sitedata.txt" ) || die( "Could not open datafile.\n" );
    print( "Enter websites below. Press Crtl-D to finish.\n" );

    while ( $x <= @sisites ) {

        $sisites[$x] = <STDIN>;

        print( "$sisites[$x] added.\n" );
        print DATAFILE ( "$sisites[$x]\n" );

        $x++;
    }

    close( DATAFILE );

    return @sisites;
}

#----------------------------------------------------------------------
# If the file exists, just get the information from it.  Read info in
# from the sites. Remember to create a global array for the sites
# data.
#-----------------------------------------------------------------------

#-----------------------------------------------------------------------
# Get the text to find in the sites that are being scraped. This requires
# nested loops. It starts by going through the loops for the text to be
# scraped, and then it goes through each of the websites listend in the
# sitedata.txt file.
#-----------------------------------------------------------------------
sub scrape_sites {
    my ( @ss_info ) = @_;

    @gsi_info = ();
    @toscrape = ();
    $y        = 1;

    #---------------------------
    # Working code to be altered
    #---------------------------
    print( "Getting site info..." );

    $x = 1;

    open( DATAFILE, "sitedata.txt" ) || die( "Can't open sitedata.txt.txt\n" );
    while ( $gsi_info[$x] = <DATAFILE> ) {

        chop( $gsi_info[$x] );
        print( "$gsi_info[$x]\n" );

        $x++;
    }

    close( DATAFILE );

    open( SCRAPEFILE, "scrpdata.txt" ) || die( "Can't open scrpdata.txt\n" );
    print( "Getting scrape data.\n" );

    $y = 1;

    while ( $toscrape[$y] = <SCRAPEFILE> ) {
        chop( $toscrape[$y] );
        $y++;
    }

    close( SCRAPEFILE );

    print( "Now opening the output file.\n" );

    $z = 1;

    open( OUTPUT, ">output.html" );
    print( "Now scraping sites.\n" );

    while ( $z <= @gsi_info ) {    #This loop contains SITES

        system( "rm -f index.html.*" );
        system( "wget $gsi_info[$z]" );

        $z1 = 1;

        print( "Searching site $gsi_info[$z] for $toscrape[$z1]\n" );
        open( TEMPFILE, "$gsi_info[$z]" );

        $comptext = <TEMPFILE>;

        while ( $comptext =~ /$toscrape[z1]/ig ) {    # This loop fetches data from the search terms

            print( "Now scraping $gsi_info[$z] for $toscrape[$z1]\n" );
            print OUTPUT ( "$toscrape[$z1]\n" );

            $z1++;
        }

        close( TEMPFILE );

        $z++;
    }

    close( OUTPUT );

    return ( @gsi_info );
}

Answer 1

您对当前工作目录的假设通常是不正确的。您似乎假设当前工作目录是脚本所在的目录，但这绝不保证，CGI脚本通常为/。

"sitedata.txt"

应该是

use FindBin qw( $RealBin );

"$RealBin/sitedata.txt"

也可能存在权限错误。当$!失败时，您应该在错误消息中包含错误原因（open），以便了解导致问题的原因！

Answer 2

在您查看某些内容时，您不会检查所有open或system来电。如果它们失败，程序将继续运行，而不会显示错误消息，告诉您原因。

您可以为所有这些添加检查，但很容易忘记。相反，请使用autodie为您进行检查。

您还希望use strict确保您没有进行任何变量拼写错误，并use warnings警告您有关小错误的信息。请参阅this answer for more。

此外@global_sites为空，因此enter_site_info()不会执行任何操作。并且scrape_sites()对其论点@ss_info没有任何作用。

Answer 3

所有这些都很有帮助。谢谢。我发现了这个问题。我正在打开错误的文件。它将错误检查放在文件上，让我发现错误。应该是

打开（TEMPFILE，“index.html”）||死（“无法打开index.html \ n”）;

我已经记住了我记得的许多建议，并将它们包含在代码中。我仍然需要实现目录建议，但这应该不难。

屏幕抓取器脚本不会写入ouptut文件

3 个答案: