从一行中提取不带定界符的固定宽度记录

我需要从单个文件中提取文本字符串，该文件包含一行很长的文本，没有定界符。使用下面的示例行，这些是以下已知事实：

??????? A1XXXXXXXXXX ??????? B1XXXX ??????? A1XXXXXXXXXX ??????? C1XXXXXXX

1.  It contains 38 fixed width record types 
2.  The record marker is a 7 alphanumeric character followed by, for example, ‘A1’.
3.  Each record type has varying widths, for example, A1 record type will have 10 characters following it, if B1 then 4, and if C1 then 7.
4.  The record types aren’t clumped together and can be in any order. As in the example, its A1,B1,A1,C1
5.  The example above has 4 records and each record type needs to go to separate files. In this case 38 of them.

??????? A1XXXXXXXXXX

??????? B1XXXX

??????? A1XXXXXXXXXX

??????? C1XXXXXXX

6.  The record identifier, e.g. ????????A1, can appear in the body of the record so cannot use grep. 
7.  With the last point in mind, I was proposing 3 solutions but not sure on how to script this and of course would greatly appreciate some help. 
a. Traverse through the file from the beginning and sequentially strip out the record to the appropriate output file. For example, strip out first record type A1 to A1file which I know is 10 characters long then re-interrogate the file which will then have B1 which I know is 4 chars long, strip this out to B1file etc.. <<< this seems painful >>
b. Traverse through the file and append some obscure character to each record marker within the same file. Much like above but not strip out. I understand it still will use the same logic but seems more elegant
c. I did think of simply using the proposed grep -oE solution but then re-interrogate the output files to see if any of the 38 record markers exist anywhere other than at the beginning. But this might not always work.

怎么样 grep

grep -oE 'A1.{10}|B1.{4}|C1.{7}' input.txt

这会将每个记录类型的每个记录打印在单独的行上。为了重定向grep输出到一个名为3个文件A1，B1，C1分别

grep -oE 'A1.{10}|B1.{4}|C1.{7}' input.txt| 
awk -v OFS= -v FS= '{f=$1$2; $1=$2=""; print>f}'

这是使用gawk的FPAT的可行解决方案

BEGIN { 
    FPAT="A1.{10}|B1.{4}|C1.{7}" #define field contents
} 
{
    for(i=1;i<=NF;i++) 
        print $i >> substr($i,0,2) #print the field to file A1,B1,etc
}

作为单线：

gawk 'BEGIN{FPAT="A1.{10}|B1.{4}|C1.{7}"} {for(i=1;i<=NF;i++)print $i >> substr($i,0,2)}' < datafile

在Perl中：

#!/usr/bin/env perl

use strict;
use warnings;
use re qw(eval);

my %field_widths = (
    A1 => 10,
    B1 =>  4,
    C1 =>  7,
    #...(fill this up with the widths of your 38 record types)
);

# Make a regex of record types; sort with longest first as appropriate for
# ... regex alternation:
my $record_type_regex = join '|', sort { length($b) <=> length($a) } keys %field_widths; 

my %records;
my $marker_length=7; #Assuming the marker is 7 characters long
while(<>){
    chomp;
    while( # Parse each line of input
      m!
        (.{$marker_length})          # Match the record marker (save in $1)
        ($record_type_regex)         # Match any record type (save in $2)
        (
         (??{'.'x$field_widths{$2})} # Match a field of correct width
        )                            # Save in $3
       !xg){
        $records{$2}.="$1$2$3\n";
      }
}
for my $file (sort keys %records){
    open my $OUT,'>',$file or die "Failed to open $file for writing: $!\n";
    print $OUT $records{$file};
    close $OUT
}

调用为：

[user@host]$ ./myscript.pl file_of_data

测试了代码，并可以使用给定的输入。

更新资料

在您的评论中，您要求上述内容与“ Unix等效”。我非常怀疑是否存在这样的事情，因为用于解析您的行的Perl表达式是一个高度不规则的表达式，并且我怀疑香草正则表达式能否解析您的给定数据格式：它与正则表达式可以处理的著名表达式类型太相似't解析（匹配任意数量的，a后跟相同数量b的）。

无论如何，我能找到的最接近的“ Unix”方法是1_CR的答案的推广。您应该注意，这种方法特定于GNU的GNU实现，grep因此不适用于大多数Unices。相反，Perl方法应该在Perl所使用的任何平台上都可以使用。这是我建议的GNU grep方法：

cat <<EOF \
| while read -r record width;do
    grep -oE ".{7}$record.{$width}" input_file\ #replace 7 with marker length
     >> "$record"
done
A1 10
B1 4
# enter your 38 record types
EOF

更新资料

根据OP在注释中的请求，可以像在脚本中那样打开文件名，而不必将文件名作为命令行参数传递：

open my $IN,'<',$input_file_name or die "Failed to open $input_file: $!\n";
while(<$IN>){ #instead of while(<>)
...

假设您已声明变量$input_file_name包含输入文件名。

至于将时间戳附加到输出文件名，您可以使用以下qx{}语法：在花括号之间可以放置所需的任何Unix命令，它将运行，并且其标准输出将代替qx{}运算符：

open my $OUT,'>',"$file_".qx{date +%Y-%m-%d--%I:%M:%S%P}

该qx运营商不局限于括号，用你最喜欢的角色作为分隔符，只要确定它不是在你需要运行下面的命令：

qx<...>
qx(...)    
qx!...!    
qx@...@

等等...

在某些Perl代码中，您可能会看到反引号（` `）代替了此功能，与shell相似。只需将qx运算符视为对任何定界符的反引号的推广即可。

顺便说一句，这将为每个文件提供稍微不同的时间戳（如果它们的创建时间之差恰好是有限的秒数）。如果您不希望这样做，可以分两个步骤进行：

my $tstamp = qx{...};
open my $OUT,'>',"$file_$tstamp" or die...;