[oracle@localhost ~]$ perl --help 


 Usage: perl [switches] [--] [programfile] [arguments] 

   -0[octal]       specify record separator (\0, if no argument) 

   -a              autosplit mode with -n or -p (splits $_ into @F) 

   -C[number/list] enables the listed Unicode features 

   -c              check syntax only (runs BEGIN and CHECK blocks) 

   -d[:debugger]   run program under debugger 

   -D[number/list] set debugging flags (argument is a bit mask or alphabets) 
  -e program      one line of program (several -e's allowed, omit programfile)
#这个参数也常用，当在后面执行命令行时；如
[oracle@localhost ~]$ perl -e' print "ok\n"'
 ok   -f              don't do $sitelib/sitecustomize.pl at startup 

   -F/pattern/     split() pattern for -a switch (//'s are optional) 

  -i[extension]   edit <> files in place (makes backup if extension supplied)
#直接在原文件上做修改！做时记得做个备份
   -Idirectory     specify @INC/#include directory (several -I's allowed) 

   -l[octal]       enable line ending processing, specifies line terminator 

   -[mM][-]module  execute "use/no module..." before executing program 

  -n              assume "while (<>) { ... }" loop around program
#当作是循环，此选项经常使用，假定一个文本有10行内容，那么如果要处理这10行，你就要加上此参数；
  -p              assume loop like -n but print line also, like sed
#暂时未看出是什么用处的
  -P              run program through C preprocessor before compilation
#在编译之前通过C预处理器运行
  -s              enable rudimentary parsing for switches after programfile
#待确定
  -S              look for programfile using PATH environment variable
#它会去$PATH目录中去寻找你要执行的程序，而不会在默认的当前目录
  -t              enable tainting warnings
#开启损坏警告
  -T              enable tainting checks
#开启损坏核对
  -u              dump core after parsing program
[oracle@localhost ~]$ cat perl01
 #!/usr/bin/perl
 print "what\n";
 [oracle@localhost ~]$ perl -u perl01
 Aborted  -U              allow unsafe operations

  -v              print version, subversion (includes VERY IMPORTANT perl info)
#直接输入perl -v 输出版本信息
  -V[:variable]   print configuration summary (or a single Config.pm variable)
#：直接输入perl -V 输出配置汇总
  -w              enable many useful warnings (RECOMMENDED)
[oracle@localhost ~]$ cat perl01
 #!/usr/bin/perl
 print what;[oracle@localhost ~]$ perl perl01
 [oracle@localhost ~]$  perl -w perl01  #因为没有在print内容上加引号的告警,虽然直接执行没有报错！
 Unquoted string "what" may clash with future reserved word at perl01 line 2.
 Name "main::what" used only once: possible typo at perl01 line 2.
 print() on unopened filehandle what at perl01 line 2.
   -W              enable all warnings  #同上 (-w) 

  -x[directory]   strip off text before #!perl line and perhaps cd to directory
#格式类似于：perl -xzbkdir  perl01  #其中zbkdir为一目录名，具体用处还不详；
  -X              disable all warnings
[oracle@localhost ~]$ perl -X perl01
 [oracle@localhost ~]$ 
 [oracle@localhost ~]$ cat perl01
 use warnings;
 #!/usr/bin/perl
 print what;
 [oracle@localhost ~]$ perl perl01
 Unquoted string "what" may clash with future reserved word at perl01 line 3.
 Name "main::what" used only once: possible typo at perl01 line 3.
 print() on unopened filehandle what at perl01 line 3.
 [oracle@localhost ~]$ perl -X perl01  #忽略里边use warnings的告警提示; 
兴例：
（1）-ne
[oracle@localhost ~]$ cat >01.txt
 first 
 second
 third

 [oracle@localhost ~]$ 
 [oracle@localhost ~]$ perl -e '
 > print;
 > ' 01.txt
 [oracle@localhost ~]$ 
 [oracle@localhost ~]$ perl -ne'
 > print;
 > ' 01.txt
 first 
 second
 third
 [oracle@localhost ~]$ 
 #可以看到只有加入了-n选项后才能将文中的内容循环的输出；（2）-i
#在原文件基础上直接修改
[oracle@localhost ~]$ perl -i -ne'
 > s/first/last/ig;
 > print;
 > ' 01.txt
 [oracle@localhost ~]$ cat 01.txt
 last 
 second
 third#以上操作要切记备份，以免悲剧发生！