perl example!

example3:
my a=OFC33L40.0
perl  '/(d+)(?=D)/ and print $1'  $

example4:
#!/opt/exp/bin/perl
use strict;
while(<>){
#       s/Q[0-9]E(?:[^+*/])/[0-9]+/g;
        s/[0-9](?:[^+*/])/[0-9]+/g;
        print;
}
#!/opt/exp/bin/perl
use strict;
my $line = 0;
while(<>){
        $line++;
        print "line7 line=$line n";
        if(s/d01/sprintf("d%02d",$line)/ge){
                print;
        }
}
example 5:
remove  felixzh1
#!/usr/bin/perl -w
use strict;
$^I = '.bak';
#read ARGV (read command line parameter file one line by one line and one file by one file)
while (<ARGV>) {
    s/felixzh1//g;
print;
}
 
it is the same with perl command line
perl  -i.bak  -pe 's/felixzh1//g' filename
 
example 6: 删除felixzh1所在的行
-n相当于-p只是不打印原来的文件内容。
-p会把每一行打出来
perl -n -e 'print unless(/felixzh1/);' < file
perl -n -e '/felixzh1/ || print' < file
perl -n -e 'print unless(/felixzh1/);' < file
perl -e 'while(<>){print unless(/felixzh1/);}' < file
perl -n -e 'print unless(/felixzh1/);' < 1.txt >2.txt
 
6.1 在diskinfo的上一行加#add by abc,在其下一行加'print (stderr,"abc line111 n")',#!/usr/bin/perl
my $dist = 'diskinfo';
while (<DATA>) {
    print /$dist/
      ? ( "#add by abcn",$_,'print (stderr,"n" )
      : $_;
}
__DATA__
fdfa
sort_diskinfo()
print1
# perl -lape '$_="#add by abcn$_nprint (stderr,"abc line111n")" if /diskinfo/' 1.txt
(la即lane可以实验去掉看看)

文本：

$ cat 9.txt
abrt-action-analyze-backtrace
abrt-action-analyze-c
abrt-action-analyze-core
abrt-action-analyze-oops
abrt-action-analyze-python
abrt-action-generate-backtrace
abrt-action-install-debuginfo
abrt-action-list-dsos
abrt-action-save-package-data
abrt-action-trim-files
abrt-applet

例子分析

#!/opt/exp/bin/perl -w
use strict;
my $file=$ARGV[0];
my $line;
my @tmp;
my $fh;
my %uniq;
my @list;
open($fh,'<',$file) or die $!;
print "line6:$file n";
while ($line=<$fh>) {
        print "line8:$line ";
      #don;t need add n,because perl read each line include "n"
       print "line9:$_ n";
      #string or list change to array
     # error1 @tmp=$line,数组将仅有一个元素. @tmp = split(/-/,$line);数组将存line分割出来的各个元素
       @tmp = split(/-/,$line);
     #输出数组
       print "line10:@tmp n";
     # print 最后元素（从最后向前print 元素）
       print "line11:$tmp[-1];$tmp[-2];$tmp[-3] n";
        #不会匹配第一个“- ”，因为有$限制
        $line =~ s/-([^-]+)$//;
        print "line12:$line n";
      #将每行的值放入数组保持
        push @list,$line;
}

# uniq 是一个哈希.哈希可以将string做为下标.?? 然后$uniq{$_}++;这样去掉了重复的行

# sort 按字母排序

my @output = sort(grep {!$uniq{$_}++} @list);

# 因为在$line =~ s/-([^-]+)$//;此处，string的n也被用空替换了，所以各个数组元素之间，要加上n区别开

# join 返回值是string,将数组变成了带n的一个string

print join("n",@output);

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

example 8:

$ cat 10.txt
wang 12 qian 45 67 sun 22
31 tang 77 89 43 li
nan 78
将数字乘以2
$ cat number.pl
#!/opt/exp/bin/perl -w
my $file = $ARGV[0];
my @tmp;
my $fh;
my $i;
open ($fh,$file) or die $!;
while (my $line=<$fh>) {
       @tmp = split(/s+/,$line);
       print "line6:@tmp";
#在正则中e表示执行函数，此句表示将数字用函数运算的结果，替换
        $line =~ s/(d+)/$1*2/eg;
          print "line16:$line n";
}

example 9:
 perl  批量更改文件名
[root@localhost test]# ls *.txt
a.txt  b.txt
[root@localhost test]# perl -e 'foreach(<*.txt>) {s/.txt$//;rename(qq{$_.txt},qq{$_-2011.txt})}'-------------------此处s/.txt$// 获取文件除去后缀名的文件名a，b
[root@localhost test]# ls *.txt
a-2011.txt  b-2011.txt
简单注释:如果文件名放到运算符（<>）中，perl会自动支持globbing。glob函数与运算符<*>点作用是完全相同的。
[root@localhost test]# perl -e 'foreach(glob("*.txt")) {s/.txt$//;rename(qq{$_.txt},qq{$_-2011.txt})}'
[root@localhost test]# ls *.txt
a-2011-2011.txt  b-2011-2011.txt
 
example 10:  删除某行,删除一行
方法1：
perl -ne 'print  if ! /^sky/' record.txt
        chihao        22        secret        提交        
        alien        25        male        提交        
       sky        20        secret        提交 
方法2：
$ perl -we '
use strict;
open(FN,"test.txt");
while(<FN>){
  next if /&;test/;
  print;
}
方法3：
open(FILE,"<a.txt"); 
@text=<FILE>;
open(FILL,">b.txt")
for(my $i=0; $i < @text; $i++)
{ 
if($text[$i] !~/bug/){
print FILL $text[$i];
} 
}
close FILL;
close FILE;
如果是空行，直接将$text[$i] !~/bug/ 替换成 $text[$i] eq ""
 
example 11:
<*> 应该是glob，类似shell里面ls所有的文件
print <> ;   cat 的perl实现,print sort <> ; sort的perl实现
正则 ^但是使用表示行首，^.后接字符表示以该字符开头

example12:   perl eval
类似java中的try{}catch{} 语句，perl中也可以捕获程序执行过程中的异常，防止因为局部异常导致程序全盘退出。
       my $a=0;
      my $b=1;
      my $c=1;
    eval {
        $c = $b/$a;
       };
        print "An error occurred:$@" if $@
      $@ 存放正常，异常的info
        注意与shell 中eval的区别
foo=10
x=foo
eval y=’$’$x
echo $y

<span style="font-family: Arial,Helvetica,sans-serif; background-color: rgb(255,255,255);"></span><pre code_snippet_id="637891" snippet_file_name="blog_20150407_6_7119606" name="code" class="html"><span style="color: rgb(51,51,51); font-family: Arial; font-size: 14px; line-height: 26px;">njcgpb:felixzh/temp/perl >> cat addline.pl</span>

<p style="color: rgb(51,51); font-family: Arial; font-size: 14px; line-height: 26px;"></p><pre name="code" class="html">#!/opt/exp/bin/perl -w
foreach my $file (glob "*.tcl") {
        print "$filen";
        &max($file);
}
sub max {
        my $dist = 'WISEOpt';
        my $line = 0;
        my $i = 0;
        my $f1 = shift @_;
        my $f2 = $f1.".bak";
        my $fd;
        my $fd2;
        open $fd,"<$f1";
        open $fd2,">$f2";
        while (<$fd>) {
                $i = $i +1;
                $line = $i;
                print $fd2 /$dist/
                ? ( "exec echo "felixzh1 $line C(RCS${rcs}WISEOpt)=$C(RCS${r
cs}WISEOpt)>>/bld/felixzh/1n"","n")
                : $_;
        }
        close $fd;
        close $fd2;
}