如何比较两个目录及其在perl中的文件 [英] How to compare two directories and their files in perl
问题描述
我正在审查中期，并审查一个老的文件我在这里发现，我想让它工作。我不能在这里找到它，但我仍然有源代码，所以我会提出另一个问题。
这是他的任务：
编写一个perl脚本，它将比较两个目录中常规文件中的差异。所有具有相同名称的常规文件应该使用unix函数/ usr / bin / diff -q进行测试，这将确定它们是否相同。在dir1中没有类似命名的文件的文件将在字符串<<<而dir2中没有相应dir1条目的文件将以字符串>>>作为前缀。如果两个文件具有相同的名称但不同，则文件名将被><。
以下是脚本：
＃！/ usr / bin / perl -w
使用File :: Basename;
@ files1 =`/ usr / bin / find $ ARGV [0] -print`;
chop @ files1;
@ files2 =`/ usr / bin / find $ ARGV [1] -print`;
chop @ files2;
语句：
for（$ i = 1; @ files1> = $ i; $ i ++）{
for（$ x = 1; @ files2> = $ x; $ x ++）{
$ file1 = basename（$ files1 [$ i]）;
$ file2 = basename（$ files2 [$ x]）;
if（$ file1 eq $ file2）{
shift @ files1;
shift @ files2;
$ result =`/ usr / bin / diff -q $ files1 [$ i] $ files2 [$ x]`;
chop $ result;
if（$ result eqFiles $ files1 [$ i]和$ files2 [$ x] different）{
print< $ file1> \\\
;
next语句;
} else {
print> $ file1< \\\
;
}
} else {
if（！-e$ files1 [$ i] / $ file2）{print>>> $ file2\\\
;}
unless（-e$ files2 [$ x] / $ file1）{print<<< $ file1\\\
;}
}
}
}
这是输出：
> file2<
>>>> file5
<<< file1
输出应为：
> file1<
> file2<
<<< file4
>>>> file5
我已经检查了文件，以确保它们都匹配，但仍然有问题。
首先，请务必使用这些：
使用strict;
使用警告;
它有一个简短的学习曲线，但它们远远弥补了它的长期。
一些备注：
- 您应该使用
File :: Find模块，而不是使用系统呼叫。 - 在数组索引1处启动循环。在perl中，第一个数组索引为0.因此，跳过第一个元素。
- 您的循环条件错误。
@files> = $ x表示您将迭代到超过max索引（通常）。你想要$ x< @files或$ x< = $＃files。 - c> chomp ，这是
chop的更安全版本。 - 更改要迭代的数组 $
if（！-e ...）然后unless（-e ...）？
这部分：
$ file1 = basename（$ files1 [$ i]）;
...
if（！-e$ files1 [$ i] / $ file2）
假设 @ files1 包含文件名，而不仅仅是目录，这绝不会匹配任何内容。例如：
$ file2 = basename（dir / bar.html）;
$ file1 = basename（foo / bar.html）;
-efoo / bar.html / bar.html; ＃不计算
查找，假设您只想匹配相同的文件名和缺少的文件名：
use strict;
使用警告;
use File :: Find;
use List :: MoreUtils qw（uniq）;
my（％files1，％files2）;
my（$ dir1，$ dir2）= @ARGV;
find（sub {-f&& $ files1 {$ _} = $ File :: Find :: name}，$ dir1）;
find（sub {-f&& $ files2 {$ _} = $ File :: Find :: name}，$ dir2）;
my @all = uniq（keys％files1，keys％files2）;
为我的$文件（@all）{
my $ result;
if（$ files1 {$ file}&& $ files2 {$ file}）{＃文件存在于两个dirs中
$ result = qx（/ usr / bin / diff -q $ files1 { $ file} $ files2 {$ file}）;
＃... etc
} elsif（$ files1 {$ file}）{＃文件只存在于dir1
} else {＃文件只存在于dir2
}
}
子程序 $ _ 代表基本名称， $ File :: Find :: name 适用于 diff ）。 -f 检查将断言您只将常规文件包含在哈希中。
Fred here again with a little issue I'm having that I hope you guys can help me with.
I'm reviewing for midterms and going over an old file I found on here and I wanted to get it working. I can't find it on here anymore but I still have the source code so I'll make another question on it.
So here was his assignment: Write a perl script that will compare two directories for differences in regular files. All regular files with the same names should be tested with the unix function /usr/bin/diff -q which will determine whether they are identical. A file in dir1 which does not have a similarly named file in dir2 will have it's name printed after the string <<< while a file in dir2 without a corresponding dir1 entry will be prefixed with the string >>>. If two files have the same name but are different then the file name will be surrounded by > <.
Here is the script:
#!/usr/bin/perl -w
use File::Basename;
@files1 = `/usr/bin/find $ARGV[0] -print`;
chop @files1;
@files2 = `/usr/bin/find $ARGV[1] -print`;
chop @files2;
statement:
for ($i=1; @files1 >= $i; $i++) {
for ($x=1; @files2 >= $x; $x++) {
$file1 = basename($files1[$i]);
$file2 = basename($files2[$x]);
if ($file1 eq $file2) {
shift @files1;
shift @files2;
$result = `/usr/bin/diff -q $files1[$i] $files2[$x]`;
chop $result;
if ($result eq "Files $files1[$i] and $files2[$x] differ") {
print "< $file1 >\n";
next statement;
} else {
print "> $file1 <\n";
}
} else {
if ( !-e "$files1[$i]/$file2") { print ">>> $file2\n";}
unless ( -e "$files2[$x]/$file1") { print "<<< $file1\n";}
}
}
}
This is the output:
> file2 <
>>> file5
<<< file1
The output should be:
> file1 <
> file2 <
<<< file4
>>> file5
I already checked the files to make sure that they all match and such but still having problems. If anyone can help me out I would greatly appreciate it!
First off, always use these:
use strict;
use warnings;
It comes with a short learning curve, but they more than make up for it in the long run.
Some notes:
- You should use the
File::Findmodule instead of using a system call. - You start your loops at array index 1. In perl, the first array index is 0. So you skip the first element.
- Your loop condition is wrong.
@files >= $xmeans you will iterate to 1 more than max index (normally). You want either$x < @filesor$x <= $#files. - You should use
chomp, which is a safer version ofchop. - Altering the arrays you are iterating over is a sure way to cause yourself some confusion.
- Why use
if (! -e ...)and thenunless (-e ...)? That surely just adds confusion.
And this part:
$file1 = basename($files1[$i]);
...
if ( !-e "$files1[$i]/$file2" )
Assuming @files1 contains file names and not just directories, this will never match anything. For example:
$file2 = basename("dir/bar.html");
$file1 = basename("foo/bar.html");
-e "foo/bar.html/bar.html"; # does not compute
I would recommend using hashes for the lookup, assuming you only want to match against identical file names and missing file names:
use strict;
use warnings;
use File::Find;
use List::MoreUtils qw(uniq);
my (%files1, %files2);
my ($dir1, $dir2) = @ARGV;
find( sub { -f && $files1{$_} = $File::Find::name }, $dir1);
find( sub { -f && $files2{$_} = $File::Find::name }, $dir2);
my @all = uniq(keys %files1, keys %files2);
for my $file (@all) {
my $result;
if ($files1{$file} && $files2{$file}) { # file exists in both dirs
$result = qx(/usr/bin/diff -q $files1{$file} $files2{$file});
# ... etc
} elsif ($files1{$file}) { # file only exists in dir1
} else { # file only exists in dir2
}
}
In the find() subroutine, $_ represents the base name, and $File::Find::name the name including path (which is suitable for use with diff). The -f check will assert that you only include regular files in your hash.
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