Question

我正在开展一个学校项目，该项目涉及一个主shell脚本，该脚本将提示用户输入包含50个单词的文本文件。如果shell脚本在shell和perl脚本所在的目录中找到该文件，它将打印一个菜单，询问用户是否要使用shell对列表进行排序并将排序后的列表输出到新文件（该文件已完成）并且工作），调用perl脚本，其中perl脚本将获取该文件并打印该文件中的所有单词，然后提示用户输入他们想要搜索的单词。这将返回列表中单词所在的行。我所做的是如果用户选择使用perl脚本进行排序，我们将shell中输入的文件通过以下方式传递给perl脚本：

cat $ filename | ./search.pl

将文件成功传送到我们可以使用它的perl脚本会发生什么。第一个while循环是我们访问列表并打印每个单词/行以供用户查看的地方，它工作正常。 但这是我遇到麻烦的地方。打印完整个列表后，printf行会询问要搜索的单词，然后程序将停止而不再允许输入，然后返回终端。我的逻辑是什么对于这个搜索脚本，我们打印每个单词供用户查看他们可以搜索的内容，然后询问他们想要搜索的内容，然后使用while循环查看shell脚本中输入的文件;如果我们找到它，打印我们在那条线上发现它，如果我们找不到它然后转到下一行，如果我们到达终点而没有找到它只是打印它不能找到。

为什么我无法通过调用STDIN输入更多输入并将其分配给$ word以在第二个while循环中使用？另外，当我正在执行第二个while循环时，正在使用＆LT;＆GT;在要求一个不同的输出去搞乱后，它本身？如果是这样，我如何再次引用第二个while循环的文件？

#!/usr/bin/env perl

$count = 1;    #global variable for return value
               # of words.

while (<>) {
    printf "$_";
}
#Now that we have opened the file, printed off everything for the user to see, they can now enter a     word in a prompt to
# see what line it is on.

printf "\nPlease enter the word you want to search for\n";
my $word = <STDIN>;
chomp $word;

while ( $line = <> ) {
    if ( $line =~ m/$word/ ) {
        print "$word has been found on line $count.\n\n";
    } elsif ( $line !=~ m/$word/ ) {
        $count++;
    } else {
        print "$word cannot be found.";
    }
}

Shell脚本（供参考）：

#!/bin/bash

clear
printf "Hello. \nPlease input a filename for a file containing a list of words you would like to use.      Please allow for one word per line.\n -> "
read filename
printf "You have entered the filename: $filename.\n"

if [ -f "$filename" ] #check if the file even exists in the current directory to use
then
    printf "The file $filename exists.  What would you like to do with this file?\n\n"
else
    printf "The file: $filename, does not exist.  Rerun this shell script and please enter a valid    file with it's proper file extension.  An example of this would be mywords.txt \n\nNow exiting.\n\n"
  exit
fi

printf "Main Menu\n"
printf "=========\n"
printf "Select 1 to sort file using Shell and output to a new file.\n"
printf "Select 2 to sort file using Perl and output to a new file.\n"
printf "Select 3 to search for a word using Perl.\n"
printf "Select 4 to exit.\n\n"

echo "Please enter your selection below"
read selection
printf "You have selected option $selection.\n"

if [ $selection -eq "1" ]
then
    read -p "What would you like to call the new file? "  newfile   #asks user what they want to call   the new file that will have the sorted list outputted to it
    sort $filename > $newfile
    echo "Your file: $newfile, has been created."
fi

if [ $selection -eq "2" ]
then
    read -p "What would you like to call the new file? "  newfile2
    cat $filename | ./sort.pl
    # > $newfile2   #put the sorted list into the new output file that the user specificed with    newfile2
fi

if [ $selection -eq "3" ]
then
    cat $filename | ./search.pl
fi

if [ $selection -eq "4" ]
then
     printf "Now exiting.\n\n"
     exit
fi

Answer 1

我修改了您的代码，如下所示。为了您的理解，我一直在发表评论，但在不需要的地方尽量避免评论。

<强>代码：

#!/usr/bin/env perl    
use strict;
use warnings;

#Input File passing as an argument to the program
my $InFile = $ARGV[0];

#Opening and reading a file using filehandle $fh
open my $fh,'<', $InFile or die "Couldn't open the file $InFile : $!"; 

while (<$fh>) {
    printf "$_";        
}

# Seek function as shown below will reset the file handle position to beginning of the file 
seek($fh, 0, 0);
printf "\nPlease enter the word you want to search for\n";
my $word = <STDIN>;
chomp $word;
my $count = 1; #global variable for return value of words               
my $val = 0;

while (my $line = <$fh>) {
    if ($line =~ m/$word/) {
        print "$word has been found on line $count.\n\n";
        $val++;
    } 
    elsif ($line !~ m/$word/) {
        $count++;
    } 
}
if ($val == 0) {
    print "$word cannot be found";
} 

close($fh);

将文件从shell脚本传递到perl脚本后请求其他输入

1 个答案: