perl 常用函數(shù)-3

努力小伙

1、將一個文件的內(nèi)容賦給一個標(biāo)量

1. #數(shù)組的每個元素對應(yīng)文件的一行
   
2. 
   
3. my @file_content = <FILE>;
   
4. 
   
5. #第二種方式，使用File::Slurp
   
6. my $filename = 'access_log';
   
7. use File::Slurp;
   
8. my @file_content = read_file($filename);

2、進(jìn)程文件句柄

接受進(jìn)程輸出

1. #接受進(jìn)程輸出
2. 
   
3. #!/usr/bin/perl -w
   
4. use strict;
   
5. use File::Slurp;
   
6. 
   
7. my $ls = 'ls -l';
   
8. 
   
9. #通過管道將進(jìn)程的輸出給句柄
   
10. open PH,"$ls |" or die "$!\n";
    
11. 
    
12. my @dir_contents = <PH>;
    
13. close PH or die "$!";
    
14. 
    
15. #print $dir_contents[0];
    
16. print "$_" for @dir_contents;
    
17. close ($ls);

向進(jìn)程句柄輸入

1. #!/usr/bin/perl -w
   
2. use strict;
   
3. use File::Slurp;
   
4. 
   
5. my $log = 'mysql.out';
   
6. open(*STDERR,">>$log");
   
7. open(*STDOUT,">>$log");
   
8. 
   
9. my $mysql = 'mysql -u root -pb7uoodi98on';
   
10. open MYSQL,"| $mysql" or die "$!";
    
11. 
    
12. select MYSQL;
    
13. print 'show databases;';
    
14. print 'use mysql;';
    
15. print 'show tables;';
    
16. close MYSQL or die "$!";

3、目錄句柄

1. #!/usr/bin/perl -w
   
2. use strict;
   
3. use File::Slurp;
   
4. 
   
5. my $homedir = '/root/lab/perl';
   
6. my $dh;
   
7. 
   
8. opendir( $dh,$homedir ) or die "$!";
   
9. 
   
10. while( my $curfile = readdir($dh) ) { #讀取目錄內(nèi)容
    
11. 
    
12.         #telldir給出目錄句柄的當(dāng)前字節(jié)位置
    
13.         my $pos = telldir $dh;
    
14.         #判斷文件是目錄還是常規(guī)文件
    
15.         my $type = -d "$homedir/$curfile" ? 'directory' : 'file';
    
16.         print "$type : $curfile pos $pos\n";
    
17. 
    
18. }
    
19. 
    
20. closedir( $dh );
    
21. 
    
22. opendir( $dh,$homedir ) or die "$!";
    
23. 
    
24. #過濾特定后綴
    
25. my @perl = grep { /\.pl|\.PL|\.pem?$/i && -f "$homedir/$_" }
    
26. readdir( $dh );
    
27. closedir( $dh );
    
28. 
    
29. print "perl code file: $_\n" for @perl;