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perl - UNIX - 根据主列比较 2 个文件

问题描述

我需要根据主列逐列比较 2 个文件（它可以是 1 个或多个列作为灵长类键）。它应该生成 3 个 csv 文件作为输出 - 差异，file1 中的额外记录，file2 中的额外记录

注意：尝试过，sdiff但没有提供所需的输出

例子 ：

这里第一列是主键

file1 :
abc 234 123
bcd 567 890
cde 678 789

file2 :
abc 234 012
bcd 532 890
cdf 678 789

Output files

differences file :
abc,234,123::012
bcd,567::532,890

extra records in file1 :
cde,678,789

extra records in file2
cdf,678,789

标签： perlunixawknawk

解决方案

如果文件可以轻松地放入内存中，那么在 Perl 中使用散列很容易。例如：

#!/bin/bash

# create test data files
>cmp.d1 cat <<'EOD'
abc 234 123
bcd 567 890
cde 678 789
EOD
>cmp.d2 cat <<'EOD'
abc 234 012
bcd 532 890
cdf 678 789
EOD

# create script
>dif.pl cat <<'EOD'
#!/usr/bin/perl -w

if ( $#ARGV!=0 or ! -f "$ARGV[0]" ) {
    die "Usage: <file2 filter file1\n";
}

@KEYS = ( 0 ); # list of columns to use for primary key

# read file1 from filename given on commandline
while (<<>>) {
    chomp;
    @a1 = (split); # split line into individual fields
    $k = join "\0", @a1[ @KEYS ];

    # if $k is not unique, only final line is kept
    warn "duplicate key: $k\n" if exists $h1{$k};

    # store line in %h1 for later use
    $h1{$k} = [ @a1 ];
}

# now read file2 from stdin
# process each line as we read it
while (<<>>) {
    chomp;
    @a2 = (split); # split line into individual fields
    $k = join "\0", @a2[ @KEYS ];

    if ( exists $h1{$k} ) {
        # record exists in both files
        # calculate differences 

        @a1 = @{ $h1{$k} }; # retrieve file1 version

        # overwrite any difference fields in @a2
        map {
            $a1 = shift @a1;
            $_ = "${a1}::$_" if $a1 ne $_;
        } @a2;

        # save difference records in %hd
        $hd{$k} = [ @a2 ];

        # this will not be an extra file1 record
        delete $h1{$k};
    }
    else {
        # this record only exists in file2
        $h2{$k} = [ @a2 ];
    }
}

# format record as csv line
sub print_csv {
    print join(",", @{ $_ }), "\n";
}

print "differences file :\n";
print_csv for values %hd;
print "\n";

print "extra records in file1 :\n";
print_csv for values %h1;
print "\n";

print "extra records in file2\n";
print_csv for values %h2;

EOD

# try it out
perl dif.pl cmp.d1 <cmp.d2

输出：

differences file :
bcd,567::532,890
abc,234,123::012

extra records in file1 :
cde,678,789

extra records in file2
cdf,678,789

注意： csv 输出通常不需要排序，因此此代码不进行任何排序。

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