概述

在perl脚本里,每行最后必须以分号结束很多时候都会去print，print自身没有换行符perl 定义变量和引用变量都需要加$[oracle@jhoa perl2]$ perl -e '$aa=xx;print "$aa" x 4 ."\n"'xxxxxxxxx 4 连续4次shell 返回值为0 表示真 非0为假Perl 返回0为假Perl 字符窜为空 为假数值比较            字符比较>                    gt>=                   ge<                    lt==                   eq!=                   ne完全和Shell相反[oracle@jhoa big]$ cat 4.pl %longday = ("Sun" => "Sunday","Mon" => "Monday","Tue" => "Tuesday","Wed" => "Wednesday","Thu" => "Thursday","Fri" => "Friday","Sat" => "Saturday",);print "$longday{Wed}\n";[oracle@jhoa big]$ perl 4.pl Wednesday[oracle@jhoa big]$ cat 5.pl $wife{"Jacob"} = ["Leah", "Rachel", "Bilhah", "Zilpah"];print "$wife{Jacob}[0]\n";[oracle@jhoa big]$ perl 5.pl Leah[oracle@jhoa big]$ cat 6.pl $var="my name is foo";if ($var =~ /foo/) { print "right\n" }[oracle@jhoa big]$ perl 6.pl right[oracle@jhoa big]$ cat 6.pl $var="my name is foo";{$var =~ s/foo/too/} { print "$var\n" }[oracle@jhoa big]$ perl 6.pl my name is too[oracle@jhoa big]$ cat 7.pl open  (FILE, "<", "aa") ;while (<FILE>){if ($_ =~ /http:/) {print $_;}}[oracle@jhoa big]$ cat aa    http://123.comaaaaaaaaahttp://123.comaaaaahttp://123.com[oracle@jhoa big]$ perl 7.pl http://123.comhttp://123.comaaaaahttp://123.comPerl代码简写:名字ASCII 定义代码空白[\t\n\r\f] \s单词[a-zA-Z_0-9] \w 包含字母和数字数字[0-9] \d\D 任何非数字 \W匹配非词[oracle@jhoa big]$ cat 13.pl $var='aaaaaa';if ( $var =~ /\w/){print "ok\n"};[oracle@jhoa big]$ perl 13.pl ok\w匹配词-------------------------------------------[oracle@jhoa big]$ cat 13.pl $var='11111';if ( $var =~ /\W/){print "ok\n"};[oracle@jhoa big]$ perl 13.pl [oracle@jhoa big]$ [oracle@jhoa big]$ cat 13.pl $var='11111';if ( $var =~ /\w/){print "ok\n"};[oracle@jhoa big]$ perl 13.pl ok-------------------------------------------\W匹配非词[oracle@jhoa big]$ cat 13.pl $var='!';if ( $var =~ /\w/){print "ok\n"};[oracle@jhoa big]$ perl 13.pl [oracle@jhoa big]$ cat 13.pl $var='!';if ( $var =~ /\W/){print "ok\n"};[oracle@jhoa big]$ perl 13.pl ok使用 \d{7,11} 将匹配最少 7 位数字， 但不会多于 11 位数字。[oracle@jhoa big]$ cat 8.pl open  (FILE, "<", "bb") ;while (<FILE>){if ($_ =~ /\d{7,11}/) {print $_;}}[oracle@jhoa big]$ perl 8.pl 123456712345678123456789123456789101234567891011？ 表示前面的子表达式零次或1次+ 表示前面的表达式一次或多次 * 匹配前面的表达式零次或多次. 匹配\n之外的任何字符perl 正则替换[oracle@jhoa big]$ cat 10.pl $str = "I love Perl";print "1.\$str is $str\n";$str =~ s/Perl/Bash/;print "2.\$str is $str\n";[oracle@jhoa big]$ perl 10.pl 1.$str is I love Perl2.$str is I love Bash-----------------------------------------------------[oracle@jhoa big]$ cat 9.pl $var = "fred xxxxxxx barney";$var =~ s/x*//;print "\$var is $var\n";[oracle@jhoa big]$ perl 9.pl $var is fred xxxxxxx barneyx*（表示零次或多次“x”) 将0个或者多个x替换为空,相当于啥也没干[oracle@jhoa big]$ cat 9.pl $var = "  fred xxxxxxx barney";print "\$var is $var\n";$var =~ s/x+//;print "\$var is $var\n";[oracle@jhoa big]$ perl 9.pl $var is   fred xxxxxxx barney$var is   fred  barney单词边界:\b匹配单词边界,就是位于单词(\w)和非单词字符(\W)之间的零宽度的地方。[oracle@jhoa big]$ cat 11.pl #$var = "The Great Fred";$var = "Frederick the Great";if ($var =~/\bFred\b/){print $var};[oracle@jhoa big]$ perl 11.pl 不能匹配Frederick the Great 因为在“Frederick”中的“d”后面没有跟着非单词字符。Fred erick the Great[oracle@jhoa big]$ cat 11.pl #$var = "The Great Fred";$var = "Fred erick the Great";if ($var =~/\bFred\b/){print $var};[oracle@jhoa big]$ perl 11.pl Fred erick the Great[oracle@jhoa big]$ 1.7.4 反引用[oracle@jhoa big]$ cat 12.pl $var = "53:02:03";if ($var =~ /\b\d{1,2}\b:\b\d{1,2}\b:\b\d{1,2}\b/){print $var};[oracle@jhoa big]$ perl 12.pl 53:02:03[oracle@jhoa big]$