我声明了一个变量
$myString'3 'SomeFun($myString)'3'#!C:\Perl\bin\perl.exe
use strict;
use warnings;
use Data::Dumper;
my $fh = \*DATA;
print Dumper parse_constant_spec( $fh );
# Parse a constant spec file.
# Pass in a handle to process.
# As long as it acts like a file handle, it will work.
sub parse_constant_spec {
my $fh = shift;
my %spec;
# Until file is done:
# Read in a whole block
while( my $block = read_block($fh) ) {
# Parse the and return key/value pairs for a hash.
my %constant = parse_block( $block );
# Store a ref to the hash in a big hash of all blocks, keyed by constant_name.
$spec{ $constant{const_name} } = \%constant;
}
# Return ref to big hash with all block data
return \%spec;
}
# Read a constant definition block from a file handle.
# void return when there is no data left in the file.
# Otherwise return an array ref containing lines to in the block.
sub read_block {
my $fh = shift;
my @lines;
my $block_started = 0;
while( my $line = <$fh> ) {
$block_started++ if $line =~ /^constant/;
if( $block_started ) {
last if $line =~ /^\s*$/;
push @lines, $line;
}
}
return \@lines if @lines;
return;
}
sub parse_block {
my $block = shift;
my ($start_line, @attribs) = @$block;
my %constant;
# Break down first line:
# First separate assignment from option list.
my ($start_head, $start_tail) = split /=/, $start_line;
# work on option list
my @options = split /\s+/, $start_head;
# Recover constant_name from options:
$constant{const_name} = pop @options;
$constant{options} = \@options;
# Now we parse the value/type specifier
@constant{'type', 'value' } = parse_type_value_specifier( $start_tail );
# Parse attribute lines.
# since we've already got multiple per line, get them all at once.
chomp @attribs;
my $attribs = join ' ', @attribs;
# we have one long line of mixed key = "value" or key = <TYPE VALUE>
@attribs = $attribs =~ /\s*(\w+\s+=\s+\w+\s+|\w+\s+=\s+".*?"|\w+\s+=\s+<.*?>)\s*/g;
for my $attrib ( @attribs ) {
warn "$attrib\n";
my ($name, $value) = split /\s*=\s*/, $attrib;
if( $value =~ /^"/ ) {
$value =~ s/^"|"\s*$//g;
}
elsif( $value =~ /^</ ) {
$value = [ parse_type_value_specifier( $start_tail ) ];
}
else {
warn "Bad line";
}
$constant{ $name } = $value;
}
return %constant;
}
sub parse_type_value_specifier {
my $tvs = shift;
my ($type, $value) = $tvs =~ /<(\w+)\s+(.*?)>/;
return $type, $value;
}
__DATA__
constant fixup GemEstabCommDelay = <U2 20>
vid = 6
name = "ESTABLISHCOMMUNICATIONSTIMEOUT"
units = "s"
min = <U2 0>
max = <U2 1800>
default = <U2 20>
constant fixup private GemConstantFileName = <A "C:\\TMP\\CONST.LOG">
vid = 4
name = "" units = ""
constant fixup private GemAlarmFileName = <A "C:\\TMP\\ALARM.LOG">
vid = 0
name = ""
units = ""
输出：
D:\learning\perl>hello1.pl
vid = 6
Bad line at D:\learning\perl\hello1.pl line 102, <DATA> line 8.
name = "ESTABLISHCOMMUNICATIONSTIMEOUT"
units = "s"
min = <U2 0>
max = <U2 1800>
default = <U2 20>
vid = 4
Bad line at D:\learning\perl\hello1.pl line 102, <DATA> line 13.
name = ""
units = ""
vid = 0
Bad line at D:\learning\perl\hello1.pl line 102, <DATA> line 18.
name = ""
units = ""
$VAR1 = {
'GemAlarmFileName' => {
'vid' => '0 ',
'options' => [
'constant',
'fixup',
'private'
],
'value' => '"C:\\\\TMP\\\\ALARM.LOG"',
'name' => '',
'type' => 'A',
'const_name' => 'GemAlarmFileName',
'units' => ''
},
'GemEstabCommDelay' => {
'vid' => '6 ',
'options' => [
'constant',
'fixup'
],
'value' => '20',
'min' => [
'U2',
'20'
],
'name' => 'ESTABLISHCOMMUNICATIONSTIMEOUT',
'max' => [
'U2',
'20'
],
'default' => [
'U2',
'20'
],
'type' => 'U2',
'units' => 's',
'const_name' => 'GemEstabCommDelay'
},
'GemConstantFileName' => {
'vid' => '4 ',
'options' => [
'constant',
'fixup',
'private'
],
'value' => '"C:\\\\TMP\\\\CONST.LOG"',
'name' => '',
'type' => 'A',
'const_name' => 'GemConstantFileName',
'units' => ''
}
};
D:\learning\perl>
您可能会注意到
'vid' => '0 ',上面的代码来自答案。我正在研究。
$myString =~ s/^\s*(.*?)\s*$/$1/;
这将修剪两侧的空白。
从右边开始：
$myString =~ s/\s*$//;
如果您的空白只是空格，那么以下代码将删除所有空格：
$mystring =~ tr/ //ds;
sub trim($)
{
my $string = shift;
$string =~ s/^\s+//;
$string =~ s/\s+$//;
return $string;
}
print trim($myString)
试试这个：
# Delete leading/trailing whitespace.
$string =~ s/^\s+|\s+$//g;
另一个潜在的替代解决方案是 CPAN 中的 Text::Trim，它将“从字符串中删除前导和/或尾随空格”。它有一个
trimsub trim
{
my $str = $_[0];
$str=~s/^\s+|\s+$//g;
return $str;
}
print trim(" 4 ");
这是一个子例程，可让您从字符串中删除前导和尾随空格，同时删除字符串中多余的空格并将其替换为单个空格。
-- routine
sub unspace {
my @stringer = @_ ? @_ : $;
$ = join( ' ', split(' ')) for @stringer;
return wantarray ? @stringer : "@stringer";
}
-- usage
$MySpacedString = ' String with tabs double-spaces and other whitespace areas. ';
$MyCleanString = unspace($MySpacedString);
删除字符串中的所有空格：
$string =~ s/ //g;
只是查看你的程序，我发现了 3 个可以改进或修复的地方。
如果我的代码格式不正确，我深表歉意。 :-(
在你的函数parse_block(...)中，有3项需要注意。
@attribs = $attribs =~ /\s*(\w+\s+=\s+\w+\s+|\w+\s+=\s+".*?"|\w+\s+=\s+<.*?>)\s*/g;
要消除 vid => '6 ' 之后的空格，只需不要在第一个子正则表达式末尾包含 \s+ 即可。
写为：
@attribs = $attribs =~ /\s*(\w+\s+=\s+\w+|\w+\s+=\s+".*?"|\w+\s+=\s+<.*?>)\s*/g;
$value = [ parse_type_value_specifier( $start_tail ) ];
你想要这个：
$value = [ parse_type_value_specifier( $value ) ];
（请注意，函数的参数应该是 $value 而不是 $start_tail。）您可能没有注意到这一点。
在 @attributes 的循环中，当“value”具有普通值（“value”中没有“”或 <...> 项）时，if/else 条件中的“else”就会执行。
更新：将
parse_type_value_specifier(...)中的参数更改为 $value。它被（错误地）表述为 $attrib。
从 Transact SQL 中的变量
$test (eq rtrim(ltrim(@sStr))$test =~s/^\s*(\S*)\s*$/$1/;
String::UtilText::Trim修剪琴弦是每个人都喜欢建造的自行车棚之一！请参阅 @szabgab 编写的简短 perlmaven 教程，了解 TIMTOWDI 乐趣的小样本。