perl 插入行

fufelixzh

请用perl实现，关键字是diskinfo，在diskinfo的前一行加#add by abc,后一行加print (stderr,"abc line111 \n")
cat 1.txt
fdfa
sort_diskinfo()
print1
输出：
fdfa
#add by abc
sort_diskinfo()
print (stderr,"abc line111 \n")
print1
--
另外
perl -pe 'print  "\n" if /diskinfo/' 2.txt
我理解这句是在diskinfo行的下面print "\n";结果却是在其上面打印print "\n"
why呢

pitonas

{:2_172:}

1. #!/usr/bin/perl
   
2. 
   
3. my $dist = 'diskinfo';
   
4. while (<DATA>) {
   
5.     print /$dist/
   
6.       ? ( "#add by abc\n", $_, 'print (stderr,"abc line111 \n")', "\n" )
   
7.       : $_;
   
8. }
   
9. 
   
10. __DATA__
    
11. fdfa
    
12. sort_diskinfo()
    
13. print1
    

复制代码

fufelixzh

回复 2# pitonas

感谢回帖
追问一下
    我理解这句是在diskinfo行的下面print "\n";结果却是在其上面打印print "\n"
perl -pe 'print  "\n" if /diskinfo/' 2.txt

如果用命令行的方式，正diskinfo行的下面print "\n";应该如何做呢

jason680

回复 1# fufelixzh

How about this

# perl -lape '$_="#add by abc\n$_\nprint (stderr,\"abc line111 \\n\")" if /diskinfo/' 1.txt
fdfa
#add by abc
sort_diskinfo()
print (stderr,"abc line111 \n")
print1

   

pitonas

{:2_172:} 师傅, this is very good
but -lape: # How about this  -lpe

回复 4# jason680


   

jason680

回复 5# pitonas


usually, I use "lane" to remember the arguement ...

fufelixzh

回复 6# jason680


    感谢回帖

pitonas

师傅, thanks! That's smart.
回复 6# jason680


   

vinian

1. perl -h
   
2. 
   
3.   -n                assume "while (<>) { ... }" loop around program
   
4.   -p                assume loop like -n but print line also, like sed
   

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kernel69

1. perl -lpe '/diskinfo/ and $_="#add by abc\n$_\nprint (stderr,\042abc line111 \\n\042)"' ff
   
2. dfa
   
3. #add by abc
   
4. sort_diskinfo()
   
5. print (stderr,"abc line111 \n")
   
6. print1

复制代码

回复 1# fufelixzh