perl 文件/路径 读写删

example8:套路模板：

8.1 读文件:

open ($fdr,"<$file")

#it is so cool,all lines can been read directly in array without while
@lineall=<$fdr>;

8.2 读文件:?

while （<fdr>） ?$line=$_;

8.3 读路径

local *DH;

opendir(DH,$item)

foreach (readdir(DH))

一次性将路径读入数组

my @subdir1=readdir ($dir);

读路径下的文件:
my $subdir="/bld/xyz/toolgeneric/328";
@files=glob("$subdir/*/*");

example3: remove folder and file which is data time before one year

#!/opt/exp/bin/perl -w
use File::Path;
my $subdir="/home/coolclf/rje/apaloads";
@files=glob("$subdir/*");
foreach my $file (@files) {
        my $mtime = (stat $file)[9];
        my @t = localtime $mtime;
       $date = sprintf "%02u/%02u/%02u %02u:%02u:%02u",$t[4] + 1,$t[3],$t[5] % 100,$t[2],$t[1],$t[0]; ####get file time status
       print $date,"n"; 
        my $a = ($t[5] % 100);
        if ($a<13) {
        #       unlink $file;             #only remove file
                print "line15:$file n";
        #       system("rm -rf $file");        #method 1 :remove folder
#               rmtree("$file");             #methold 2:remove folder
                unlink <$file/*>;            #method 3:remove folder
                rmdir $file;
        }
}

example4:remove.pl 有数字比较和unless 和rm folder和时间

 #!/opt/exp/bin/perl -w

use File::Path;
my $subdir="/opt/cool2b";
my @files=glob("$subdir/*");

foreach my $file (@files) {
#print "file=$filen";
@array=stat("$file");
my $mtime = (stat $file)[9];
my @t = localtime $mtime;
my $year = ($t[5] % 100);

# print ("line13:year=$year;$t[5]n");
# if ( $year eq "9" || $year eq "10" || $year eq "11" || ) {
if ( $year > 8 && $year < 10 ) {
print "line15:file=$filen";
rmdir $file;
}
#$date = sprintf "%02u/%02u/%02u %02u:%02u:%02u",$t[0];
# print $date,"n";

$uid=$array[4];
# my $name="";
$name=(getpwuid $uid)[0];
# ($name,$passwd,$uid,$gid,$quota,# $comment,$gcos,$dir,$shell) = getpwuid($uid);
#if ( defined ($name) ) {
unless ( defined ($name) ) {
# print ("file=$file;uid=$uid;name=$namen");
# print ("line25:file=$filen");
# rmdir $file;
}
# if ($name ne "" ) {
# if ( $name ) {
# print ("file=$file;uid=$uid;name=$namen");
# }
}

example1: read from command line

钻石操作符<>是perl的读取文件每一行的操作符,是一个整行输入操作符的特例

#!/opt/exp/bin/perl -w
sub say {
        print @_,"n";
}
my $file =$ARGV[0];
open (my $fh,'<',$file) or die $!;
#@a=<$fh> read file to array; then while read array one by one
while (my $line=<$fh>) {
        if ($line =~ /^bjmcl0(dd)/) {
                if ($1>=33 and $1<=63) {
                       #read from $_
                       $line=~s/^/#/;
                }
        }
        # print $line."n";
        say $line;
}

example2: read and write files

#!/opt/exp/bin/perl
print "nOpen a text file.n";
open IN,"<data1.txt";  #read a text file
my @raw=<IN>;           #using @raw store data
chomp(@raw);            #skip enter keys
close(IN);
#print "@raw n";
my @ref;                #make 2d array
                        #'$#' = length of @raw
for ($i = 0 ; $i <= $#raw ; $i++) {
    my @tmp = split(/s/,$raw[$i]);
       $ref[$i]=@tmp; #each line is a refence in @ref
        print "$i;$ref[$i];$tmp[$i] n";
       
    }

#!/opt/exp/bin/perl -w

open my $fh,'1';
open my $fd,">>","2";
while (my $line=<$fh>) {
	print $fd $line;
}

close ($fh);
close ($fd);

下面这段网络的思路我觉得挺对的：留下来仅供参考

做工程就应该是这样，熟练于一种，应用后组合

"我只知道一种操作符，>,而且每次都只会这么写

open(my $fh,'>','filename') or die $!;

实在搞不清楚那么多的读写符号。我在读写文件时，现在只用 File::Slurp?模块的
read_file write_file 函数接口。

在处理文件时，我很少把输出文件和输入文件设置成一个。因为一旦搞错，数据就毁了。

通常是，设置两个不同的文件，一个读，一个写，经过确认没有问题后，也不敢把原先的文件覆写。而是备份起来。

遍历文件中，对于忽略的行，通常用 next 那么在新文件中就不出现了"

===================================

#!/opt/exp/bin/perl -w
open my $fh,'1-2.txt' or die $!;
while ($line=<$fh>) {
        if ($line=~/felixzh1/) {
                #       $line=~s/.*//g;
                next;
        }
        print $fh1 $line;
}
close $fh

example 6: 遍历subdirectory files

grep /bld/xyz/toolgeneric/328/*/*

<pre code_snippet_id="637883" snippet_file_name="blog_20150407_5_4549377" name="code" class="html">ARGV表示命令行参数

#!/opt/exp/bin/perl -wmy $dir=$ARGV[0];print "$dir n";my $fd;#my @subdir1=readdir ($dir);#print @subdir1;my $subdir="/bld/xyz/toolgeneric/328";@files=glob("$subdir/*/*");----------------------globe define files#print "line10 @files n";

foreach my $file(@files) {
        print "line12:$file n";
        my $fh;
        open ($fh,$file) or next;
        while (<$fh>) {
                if (/xyz/) {
                        print "xyz line17 $file:,$_";
                }
        }
        close($fh);
}

</pre><pre code_snippet_id="637883" snippet_file_name="blog_20150407_5_4549377" name="code" class="html">example7:

special variables----INPLACE_EDIT

<p>$^I?? 内置控制编辑器的值--------------------------仅用于读写同一文件
#!/usr/bin/perl -w
use strict;
$^I = '.bak';
while (<ARGV>) {
??? s/felixzh1//g;
print;
}</p>

example 9 ?find2?查找路径--递归

#!/opt/exp/bin/perl -w

use strict;
use warnings;

sub lsr {
? ? sub lsr;
? ? my $cwd = shift;

? ? local *DH;
? ? if (!opendir(DH,$cwd)) {
? ? ? ? warn "Cannot opendir $cwd: $! $^E";
? ? ? ? return undef;
? ? }
? ? foreach (readdir(DH)) {
? ? ? ? if ($_ eq '.' || $_ eq '..') {
? ? ? ? ? ? next;
? ? ? ? }
? ? ? ? my $file = $cwd.'/'.$_;
? ? ? ? if (!-l $file && -d _) {
? ? ? ? ? ? $file .= '/';
? ? ? ? ? ? lsr($file);
? ? ? ? }
? ? ? ?# process($file,$cwd);
? ? ? ? process($file);
? ? }
? ? closedir(DH);
}

my ($size,$dircnt,$filecnt) = (0,0);

sub process($$) {
? ? my $file = shift;
? ? print $file,"n";
? ? if (substr($file,length($file)-1,1) eq '/') {
? ? ? ? $dircnt++;
? ? }
? ? else {
? ? ? ? $filecnt++;
? ? ? ? $size += -s $file;
? ? }
}

lsr('.');
print "$filecnt files,$dircnt directory. $size bytes.n";

example 10: find ?非递归

use strict;
use warnings;

sub lsr_s {
    my $cwd = shift;
    my @dirs = ($cwd.'/');

    my ($dir,$file);
    while ($dir = pop(@dirs)) {
        local *DH;
        if (!opendir(DH,$dir)) {
            warn "Cannot opendir $dir: $! $^E";
            next;
        }
        foreach (readdir(DH)) {
            if ($_ eq '.' || $_ eq '..') {
                next;
            }
            $file = $dir.$_;         
            if (!-l $file && -d _) {
                $file .= '/';
                push(@dirs,$file);
            }
           # process($file,$dir);
            process($file);
        }
        closedir(DH);
    }
}

my ($size,0);

sub process($$) {
    my $file = shift;
    print $file,"n";
    if (substr($file,1) eq '/') {
        $dircnt++;
    }
    else {
        $filecnt++;
        $size += -s $file;
    }
}

lsr_s('.');
print "$filecnt file