perl - 如何保留 perl 变量的尾随空格？

Question

脚本(最初从 here 复制)将固定宽度的文本文件作为输入，重新排列列的顺序，并应输出固定宽度的文本文件。但是尾随空格被从变量中截断，这意味着输出不是固定宽度的。

open(INPUT, "</home/ecom/tmp/citiBIG/GROUP.txt");
open(OUTPUT, ">/home/ecom/tmp/citiBIG/GROUP2.txt");

my $LINEFORMAT = "A2 A7 A14 A4 A2 A2 A4 A12 A25 A30 A26 A40 A40 A40 A25 A4 A12 A14 A2 A8 A12 A70 A8"; # Adjust to your
 field widths

while(<INPUT>) {
    chomp;
    my($Null0, $EmpNum, $CcNumber, $Null1, $CcExpYy, $CcExpMm, $Null2, $Title, $LastName, $FirstName, $HolderName, $Ad
dress1, $Address2, $Address3, $Suburb, $State, $PostCode, $Null3, $AreaCode, $WorkPhone, $Null4, $Email, $GroupName) =
 unpack($LINEFORMAT, $_);

    print OUTPUT $EmpNum . "               " . "~" . $LastName . "~" . $FirstName . "~" . $Title . "        " . "~" .
$Address1 . "~" . $Address2 . "~" . $Address3 . "~" . $Suburb . "~" . $PostCode . "~" . $State . "~" . $AreaCode . "~"
 . $WorkPhone . "~" . $CcNumber . "~" . $CcExpMm . "~" . $CcExpYy . "~" . $HolderName . "~" . $Email . "~" . $GroupNam
e . "                      " . "~" . "\n";
}


close INPUT;
close OUTPUT;

Answer 1

perldoc -f pack 建议:

              o   The "a", "A", and "Z" types gobble just one value, but pack
               it as a string of length count, padding with nulls or
               spaces as needed.  When unpacking, "A" strips trailing
               whitespace and nulls, "Z" strips everything after the first
               null, and "a" returns data without any sort of trimming.

或许您可以尝试在格式字符串中使用“a”而不是“A”？或者，您可以使用 printf 将输出字段填充到所需的宽度。