perl-将 sed 翻译为 perl

perl-将 sed 翻译为 perl

以下命令在 Solaris 上运行良好(仅当最后一个字符为“:”时才删除行)

 sed -e '/:$/d' < foo > foo.new

如何在 perl 中执行相同操作?(原因是我不想创建新文件)

  perl -i -pe 's/:$/d' foo
  Substitution replacement not terminated at -e line 1.

答案1

类似于:

perl -ne ‘打印除非 /:$/’
perl -ne‘如果!/:$/则打印’
perl -ne'!/:$/&&打印'

sed -i请注意,和都是perl -i通过创建临时文件并替换原始文件来工作的。如果您也想避免这种情况,请使用ed

ed 文件 <<'EOF'
克/:$/天
吴庆
末梢血

答案2

Perl 带有 sed-to-perl 转换器,s2p。仅出于兴趣,s2p '/:$/d'给出:

#!/usr/local/bin/perl -w
eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}'
  if 0;
$0 =~ s/^.*?(\w+)[\.\w+]*$/$1/;

use strict;
use Symbol;
use vars qw{ $isEOF $Hold %wFiles @Q $CondReg
             $doAutoPrint $doOpenWrite $doPrint };
$doAutoPrint = 1;
$doOpenWrite = 1;
# prototypes
sub openARGV();
sub getsARGV(;\$);
sub eofARGV();
sub printQ();

# Run: the sed loop reading input and applying the script
#
sub Run(){
    my( $h, $icnt, $s, $n );
    # hack (not unbreakable :-/) to avoid // matching an empty string
    my $z = "\000"; $z =~ /$z/;
    # Initialize.
    openARGV();
    $Hold    = '';
    $CondReg = 0;
    $doPrint = $doAutoPrint;
CYCLE:
    while( getsARGV() ){
        chomp();
        $CondReg = 0;   # cleared on t
BOS:;
# /:$/d
if( m /:$/s )
{ $doPrint = 0;
  goto EOS;
}

EOS:    if( $doPrint ){
            print $_, "\n";
        } else {
            $doPrint = $doAutoPrint;
        }
        printQ() if @Q;
    }

    exit( 0 );
}
Run();

# openARGV: open 1st input file
#
sub openARGV(){
    unshift( @ARGV, '-' ) unless @ARGV;
    my $file = shift( @ARGV );
    open( ARG, "<$file" )
    || die( "$0: can't open $file for reading ($!)\n" );
    $isEOF = 0;
}

# getsARGV: Read another input line into argument (default: $_).
#           Move on to next input file, and reset EOF flag $isEOF.
sub getsARGV(;\$){
    my $argref = @_ ? shift() : \$_;
    while( $isEOF || ! defined( $$argref = <ARG> ) ){
        close( ARG );
        return 0 unless @ARGV;
        my $file = shift( @ARGV );
        open( ARG, "<$file" )
        || die( "$0: can't open $file for reading ($!)\n" );
        $isEOF = 0;
    }
    1;
}

# eofARGV: end-of-file test
#
sub eofARGV(){
    return @ARGV == 0 && ( $isEOF = eof( ARG ) );
}

# makeHandle: Generates another file handle for some file (given by its path)
#             to be written due to a w command or an s command's w flag.
sub makeHandle($){
    my( $path ) = @_;
    my $handle;
    if( ! exists( $wFiles{$path} ) || $wFiles{$path} eq '' ){
        $handle = $wFiles{$path} = gensym();
        if( $doOpenWrite ){
            if( ! open( $handle, ">$path" ) ){
                die( "$0: can't open $path for writing: ($!)\n" );
            }
        }
    } else {
        $handle = $wFiles{$path};
    }
    return $handle;
}

# printQ: Print queued output which is either a string or a reference
#         to a pathname.
sub printQ(){
    for my $q ( @Q ){
        if( ref( $q ) ){
            # flush open w files so that reading this file gets it all
            if( exists( $wFiles{$$q} ) && $wFiles{$$q} ne '' ){
                open( $wFiles{$$q}, ">>$$q" );
            }
            # copy file to stdout: slow, but safe
            if( open( RF, "<$$q" ) ){
                while( defined( my $line = <RF> ) ){
                    print $line;
                }
                close( RF );
            }
        } else {
            print $q;
        }
    }
    undef( @Q );
}

答案3

如果最后一个字符是“:”则删除行

perl -i -nle'/:$/||print' myfile
perl -i -nle'print unless /:$/' myfile            #same thing

http://perldoc.perl.org/perlrun.html有关 -i -n -l 和 -e 的解释。

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