GNU General Public License, which may be foundinthe Perl5source kit. Complete documentationforPerl, including FAQ lists, should be foundonthissystemusing"man perl"or"perldoc perl". If you have access to the Internet, point your browser at http://www.perl.org/, the Perl Home Page.12345678 ...
O_RDONLY Read only.O_WRONLY Write only.O_RDWR Readandwrite.O_CREAT Create the fileifit doesn.t already exist.O_EXCL Failifthe file already exists.O_APPEND Append to an existing file.O_TRUNC Truncate the file before opening.O_NONBLOCK Non-blocking mode.O_NDELAY Equivalent of O_NONBLOCK.O_...
Example 2: Check Whether the File Is Empty or Do Not Exist Create a Perl file with the following script that takes the filename from the user, and check whether the file is empty or not using the “-z” file test operator. If the operator returns true, a line of text will be writt...
if ($output_file) { print "Output will be saved to $output_file\n"; } Ⅱ、需要实现更复杂的逻辑,比如参数的默认值、互斥选项、参数的重复等 示例: #!/usr/bin/perl use strict; use warnings; use Getopt::Long; my $input_file = “./input_file.txt”; ...
mkdir('d:\test',0755)||die "can't create directory: $!" ; 删除目录 rmdir('d:\perl\wzj')||die "can't remove diretory: $!"; 在某一目录内找指定文件 usestrict ;useFile::Find ;subwanted{if($_eq"311.txt"){print$File::Find::name;print"\n"; } } find \&wanted ,"d:/"; ...
open BEDROCK, ">", $file_name; open LOG, ">>", &logfile_name(); Bad 文件句柄 关闭文件句柄 close BEDROCK; 严重错误和 die 可以和 C 中使用 perror 类似,用 die 函数: if (!open LOG, ">>logfile") { die "Cannot create logfile:$!"; ...
否定真正的价值! 或not返回特殊的假值。 Perl编程语言提供以下类型的条件语句。 Sr.No.声明和说明 (The ? : Operator) 我们检查conditional operator ? : conditional operator ? :可用于替换if...else语句。 它有以下一般形式 - Exp1 ? Exp2 : Exp3; 12...
Create a Perl file with the following script that takes the filename and search string from the user to search the string value in the file content. The open() function is used in the script to open the file to read if the filename that is taken from the user exists in the current ...
O_CREAT Create the file if it doesn.t already exist. O_EXCL Fail if the file already exists. O_APPEND Append to an existing file. O_TRUNC Truncate the file before opening. O_NONBLOCK Non-blocking mode. O_NDELAY Equivalent of O_NONBLOCK. ...
file location; # check if file exist, if not create. # running running 'process matching part'; # check the existence of running processes through the specified command-line string pattern. if no processes match the pattern, make the current rule fail immediately. ...