perl读写文件和命令行解析
发布时间：2020-12-16 00:16:42 所属栏目：大数据 来源：网络整理
导读：? 一 读写文件 实例：?? use ?strict; use ?warnings; sub ?open_display_file { ?? # ?the?filename?should?be?passed?in?as?a?parameter ?? my ? $filename ? = ? shift ; ?? # ?open?file?to?the?handle?FILE ?? open (FILE , ? $filename )? || ? die ?
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? 一 读写文件 实例：??
use
?strict;
use ?warnings; sub ?open_display_file { ?? # ?the?filename?should?be?passed?in?as?a?parameter ?? my ? $filename ? = ? shift ; ?? # ?open?file?to?the?handle?<FILE> ?? open (FILE , ? $filename )? || ? die ? " Could?not?read?from?$filename,?program?halting. " ; ?? # ?read?the?first?line,?and?chomp?off?the?newline ?? chomp ( my ? $firstline ? = ? < FILE > ); ?? print ? $firstline ; ?? # ?read?other?into?array ?? my ? @other ? = ? < FILE > ; ?? print ? @other ; ?? close ?FILE;?? } # ?a?test?to?show?how?to?call?my?function & open_display_file( ' test.txt ' ); ?注释： 1)handle句柄，概念类似C++中的资源句柄，常用的打开文件时返回句柄。句柄使用类似<handle>，系统默认的输入输出句柄为<STDIN>，<STDOUT>和<STDERR>。 7）在if中可以使用一下option来判断文件：
8）打开文件时控制为读写属性，如下：?
? 二 命令行解析 1）调用perl的时候使用-s选项，例如perl?-s?commandline.pl?-a?-b=12?-c=foo?-d=bar，然后在文件中使用$a,$b,$c,$d选项，实例如下：
#
commandline.pl
use ?strict; use ?warnings; my ? $usage ? = ? << EOU; usage? : ?[ - a]?[ - b=num]?[ - c=str1]?[ - d=str2] ???? - a? == ?a?option ???? - b? == ?b?option ???? - c? == ?c?option ???? - d? == ?d?option EOU print ? $usage ; if ( our ? $a )?{ print " a?option?is?used!n " ;} if ( our ? $b )?{ print " b?option?is?used!?and?the?value?is?$bn " ;} if ( our ? $c )?{ print " c?option?is?used!?and?the?value?is?$cn " ;} if ( our ? $d )?{ print " d?option?is?used!?and?the?value?is?$dn " ;} # calling #perl?-s?commandline.pl?-a?-b=12?-c=foo?-d=bar #output #usage?:?[-a]?[-b=num]?[-c=str1]?[-d=str2] #???????-a?==?a?option #???????-b?==?b?option #???????-c?==?c?option #???????-d?==?d?option #a?option?is?used! #b?option?is?used!?and?the?value?is?12 #c?option?is?used!?and?the?value?is?foo #d?option?is?used!?and?the?value?is?bar ?? 2）使用Getopt::Long或Getopt::Std,在perl文件开始使用use?Getopt::Long;GetOptions("a!",?"b=i",?"c=s",?"d:s");，然后在文件中使用选项$opt_a，$opt_b,$opt_c,$opt_d,调用为perl?commandline2.pl?-a?-b=12?-c=foo?-d=bar，实例如下：
#
commandline2.pl
use ?strict; use ?warnings; my ? $usage ? = ? << EOU; usage? : ?[ - a]?[ - b=num]?[ - c=str1]?[ - d=str2] ???? - a? == ?a?option ???? - b? == ?b?option ???? - c? == ?c?option ???? - d? == ?d?option EOU print ? $usage ; use ?Getopt :: Long; # use?Getopt::Std; GetOptions( " a! " , ? " b=i " , ? " c=s " , ? " d:s " ); if ( our ? $opt_a )?{ print " a?option?is?used!n " ;} if ( our ? $opt_b )?{ print " b?option?is?used!?and?the?value?is?$opt_bn " ;} if ( our ? $opt_c )?{ print " c?option?is?used!?and?the?value?is?$opt_cn " ;} if ( our ? $opt_d )?{ print " d?option?is?used!?and?the?value?is?$opt_dn " ;} # calling #perl?commandline2.pl?-a?-b=12?-c=foo?-d=bar #output #usage?:?[-a]?[-b=num]?[-c=str1]?[-d=str2] #???????-a?==?a?option #???????-b?==?b?option #???????-c?==?c?option #???????-d?==?d?option #a?option?is?used! #b?option?is?used!?and?the?value?is?12 #c?option?is?used!?and?the?value?is?foo #d?option?is?used!?and?the?value?is?bar ? 3) 自己解析，调用为perl?commandline3.pl?-a?-b12?-cfoo?-dbar，如下：
use
?strict;
use ?warnings; my ? $usage ? = ? << EOU; usage? : ?[ - a]?[ - bnum]?[ - cstr1]?[ - dstr2] ???? - a? == ?a?option ???? - b? == ?b?option ???? - c? == ?c?option ???? - d? == ?d?option EOU print ? $usage ; my ? $a ? = ? 0 ; my ? $b ? = ? 0 ; my ? $c ? = ? 0 ; my ? $d ? = ? 0 ; foreach ? my ? $arg ?( @ARGV ) { ???? if ?( $arg ? =~/^- a$ / i){ $a ? = ? 1 ;} ???? elsif ?( $arg ? =~/^- b( .* )$ / i)?{ $b ? = ?$ 1 ;} ???? elsif ?( $arg ? =~/^- c( .* )$ / i)?{ $c ? = ?$ 1 ;} ???? elsif ?( $arg ? =~/^- d( .* )$ / i)?{ $d ? = ?$ 1 ;} } if ( $a )?{ print " a?option?is?used!n " ;} if ( $b )?{ print " b?option?is?used!?and?the?value?is?$bn " ;} if ( $c )?{ print " c?option?is?used!?and?the?value?is?$cn " ;} if ( $d )?{ print " d?option?is?used!?and?the?value?is?$dn " ;} # calling #perl?commandline3.pl?-a?-b12?-cfoo?-dbar #output #usage?:?[-a]?[-bnum]?[-cstr1]?[-dstr2] #???????-a?==?a?option #???????-b?==?b?option #???????-c?==?c?option #???????-d?==?d?option #a?option?is?used! #b?option?is?used!?and?the?value?is?12 #c?option?is?used!?and?the?value?is?foo #d?option?is?used!?and?the?value?is?bar ?? 4) 在windows还可以封装为cmd文件，调用为commandline3.cmd -a -b12 -cfoo -dbar，如下：
@rem
?
=
?
'
@echo?off perl?-S commandline3.cmd?%1?%2?%3?%4?%5?%6?%7?%8?%9 goto?endofperl @rem? ' ; # ?The?above?is?pretty?ugly,?but?required?for?DOS/NT?use.?? # #!/bin/perl # #?commandline3.cmd use ?strict; use ?warnings; my ? $usage ? = ? << EOU; usage? : ?[ - a]?[ - bnum]?[ - cstr1]?[ - dstr2] ???? - a? == ?a?option ???? - b? == ?b?option ???? - c? == ?c?option ???? - d? == ?d?option EOU print ? $usage ; my ? $a ? = ? 0 ; my ? $b ? = ? 0 ; my ? $c ? = ? 0 ; my ? $d ? = ? 0 ; foreach ? my ? $arg ?( @ARGV ) { ???? if ?( $arg ? =~/^- a$ / i){ $a ? = ? 1 ;} ???? elsif ?( $arg ? =~/^- b( .* )$ / i)?{ $b ? = ?$ 1 ;} ???? elsif ?( $arg ? =~/^- c( .* )$ / i)?{ $c ? = ?$ 1 ;} ???? elsif ?( $arg ? =~/^- d( .* )$ / i)?{ $d ? = ?$ 1 ;} } if ( $a )?{ print " a?option?is?used!n " ;} if ( $b )?{ print " b?option?is?used!?and?the?value?is?$bn " ;} if ( $c )?{ print " c?option?is?used!?and?the?value?is?$cn " ;} if ( $d )?{ print " d?option?is?used!?and?the?value?is?$dn " ;} # calling #perl?commandline3.cmd?-a?-b12?-cfoor?-dbar #output #usage?:?[-a]?[-bnum]?[-cstr1]?[-dstr2] #???????-a?==?a?option #???????-b?==?b?option #???????-c?==?c?option #???????-d?==?d?option #a?option?is?used! #b?option?is?used!?and?the?value?is?12 #c?option?is?used!?and?the?value?is?foo #d?option?is?used!?and?the?value?is?bar exit ?( 1 ); __END__ : ?endofperl ? ? ?完！ （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
