chop和chomp: my $line = “hello\n”; chomp $line; #删掉$line末尾的”\n”($/指定) chop $line; #删除$line最后一个字符 split和join: #切割函数、胶水函数 $str = “A:B:C”; my @arr = split/:/,$str; # @arr = qw(A B C) $str = join(“,”,@arr); # $str=“A,B,C” ...
Perl语言(https://www.perl.org/)最初是为文件体系处理而创作的一种多用途语言,Perl试图填补低级语言(如C、C++或汇编语言)和高级语言(如shell编程)之间的空白,使其既满足快速编程,又具有灵活的文本处理功能。Perl简单好用,但是比较难学,Perl为了提高运行速度,拥有大量简写、缩写,并拥有灵活的正则表达式系统,使得完...
This is the syntaxforhere documentandit willcontinueuntil it encounters a EOF in the first line. This iscaseofdoublequote so variable value will be interpolated. For example value of a =$aEOFprint"$var\n";$var= <<'EOF'; This iscaseof single quote so variable value will be interpolated....
The line variable is now $VAR1 = 'use strict; '; 2 : use strict; The line variable is now $VAR1 = ' '; 3 : The line variable is now $VAR1 = 'foreach (0..20) '; 4 : foreach (0..20) The line variable is now $VAR1 = '{ '; 5 : { The line variable is now $VA...
if(notdefined($line)){//判断是否EOF } close(IN_FILE)//关闭文件 建议对读出来的东西都进行chomp,去掉"\n" 写入文件: openOUT_FILE">data.txt"//打开data.txt,“>”是一个特殊字符,表示要写入 printOUT_FILE"hello\n" 【编辑推荐】 Perl基础 Perl数组学习指南...
基本上,只要子程序名称不和内置函数同名,或者有特殊需求时(如需要明确子程序的名称时,如defined(&mysub)),都可以省略& 不能在使用了&、有参数传递的情况下,省略括号 最安全、最保险的调用方式是: 有参数时:&subname(arg1,arg2),即不省略&和括号 无参数时:&subname 代码如下(示例): # 定义一个函数 sub...
}else{print"Y is notdefined\n"; } 输出: X isdefinedY is notdefined 范例2: #!/usr/bin/perl# Defining a functionsubX{# Defining a variable$VAR =20; }# Checking for existence of $X# withdefined() functionif(defined(X)) {print"Function Exists\n"; ...
defined Returns a Boolean value telling whether EXPR has a value other than the undefined valueundef. If EXPR is not present,$_will be checked. Many operations returnundefto indicate failure, end of file, system error, uninitialized variable, and other exceptional conditions. This function allows...
#!/usr/bin/perl # Global variable $string = "Hello, World!"; # Function definition sub PrintHello { # Private variable for PrintHello function my $string; $string = "Hello, Perl!"; print "Inside the function $string\n"; } # Function call PrintHello(); print "Outside the function ...
I try to check if my gateway's IP matches with a defined value. For this, I catch the IP into a variable using qx() then I run an if statement: #!/usr/bin/perl $a = qx(ip ro ls | grep default | cut -d ' ' -f3 ); print "a = ${a}\n"; $b = "123.456.789.111";...