perl

How to see if a directory exists or not in Perl?

由 烂漫一生 提交于 2020-12-29 01:47:26
问题 To see if a file exists before using it, we can use: if (-e "filename.cgi") { #proceed with your code } But how to indentify a directory exists or not? 回答1: Use -d (full list of file tests) if (-d "cgi-bin") { # directory called cgi-bin exists } elsif (-e "cgi-bin") { # cgi-bin exists but is not a directory } else { # nothing called cgi-bin exists } As a note, -e doesn't distinguish between files and directories. To check if something exists and is a plain file, use -f . 来源： https:/

How to see if a directory exists or not in Perl?

由 北慕城南 提交于 2020-12-29 01:42:27
问题 To see if a file exists before using it, we can use: if (-e "filename.cgi") { #proceed with your code } But how to indentify a directory exists or not? 回答1: Use -d (full list of file tests) if (-d "cgi-bin") { # directory called cgi-bin exists } elsif (-e "cgi-bin") { # cgi-bin exists but is not a directory } else { # nothing called cgi-bin exists } As a note, -e doesn't distinguish between files and directories. To check if something exists and is a plain file, use -f . 来源： https:/

CentOs7安装mysql

由 六月ゝ 毕业季﹏ 提交于 2020-12-29 00:32:49
yum install perl perl-devel cd /usr/local/src wget https://cdn.mysql.com//Downloads/MySQL-5.6/mysql-5.6.40-linux-glibc2.12-x86_64.tar.gz tar zxvf mysql-5.6.40-linux-glibc2.12-x86_64.tar.gz mv mysql-5.6.40-linux-glibc2.12-x86_64 /usr/local/mysql useradd -s /sbin/nologin mysql 创建存放数据的目录: mkdir -p /data/mysql chown -R mysql:mysql /data/mysql/ 执行: cd /usr/local/mysql ./scripts/mysql_install_db --user=mysql --datadir=/data/mysql 配置文件: cp support-files/my-default.conf /etc/my.cnf cp support-files/mysql.server /etc/init.d/mysqld chmod 755 /etc/init.d/mysqld vim /etc/init.d/mysqld ,在配置里找到 basedir

moving sql logic to backend - bash

由 无人久伴 提交于 2020-12-27 05:51:26
问题 One of the sql logic is moving to backend and I need to generate a report using shell scripting. For understanding, I'm making it simple as follows. My input file - sales.txt (id, price, month) 101,50,2019-10 101,80,2020-08 101,80,2020-10 201,100,2020-09 201,350,2020-10 The output should be for 6 months window for each id e.g t1=2020-07 and t2=2020-12 101,50,2020-07 101,80,2020-08 101,80,2020-09 101,80,2020-10 101,80,2020-11 101,80,2020-12 201,100,2020-09 201,350,2020-10 201,350,2020-11 201

moving sql logic to backend - bash

由 十年热恋 提交于 2020-12-27 05:50:46
问题 One of the sql logic is moving to backend and I need to generate a report using shell scripting. For understanding, I'm making it simple as follows. My input file - sales.txt (id, price, month) 101,50,2019-10 101,80,2020-08 101,80,2020-10 201,100,2020-09 201,350,2020-10 The output should be for 6 months window for each id e.g t1=2020-07 and t2=2020-12 101,50,2020-07 101,80,2020-08 101,80,2020-09 101,80,2020-10 101,80,2020-11 101,80,2020-12 201,100,2020-09 201,350,2020-10 201,350,2020-11 201

moving sql logic to backend - bash

由 ＊爱你＆永不变心＊ 提交于 2020-12-27 05:50:02
问题 One of the sql logic is moving to backend and I need to generate a report using shell scripting. For understanding, I'm making it simple as follows. My input file - sales.txt (id, price, month) 101,50,2019-10 101,80,2020-08 101,80,2020-10 201,100,2020-09 201,350,2020-10 The output should be for 6 months window for each id e.g t1=2020-07 and t2=2020-12 101,50,2020-07 101,80,2020-08 101,80,2020-09 101,80,2020-10 101,80,2020-11 101,80,2020-12 201,100,2020-09 201,350,2020-10 201,350,2020-11 201

XML::LibXML issue finding XML nodes with a namespace

由 被刻印的时光 ゝ 提交于 2020-12-26 08:21:26
问题 I am writing an XML parser and am having an issue with the program handling a link. I am attempting to parse an XML hierarchy Settings/Setting then findnode 'Value'. The following is an example of the XML: <?xml version='1.0' ?> <Settings xmlns='http://hme.com/Settings.xsd'> <Setting SID="0"> <Name>Store ID</Name> <Value>72</Value> </Setting> <Setting SID="1"> <Name>Deprecated</Name> <Value>0</Value> </Setting> <Setting SID="8"> <Name>Open Store Hours Sunday</Name> <Value>25200</Value> <

use strict; behaviour not working as expected in Perl wrt $a and $b

由 最后都变了- 提交于 2020-12-26 07:55:03
问题 I have written a sample perl code: use strict; use warnings; $a=1; $b=2; if($b==2) { $a=3; } print $a; Ideally, when I run this code, it should give an error as 'Global symbol "$a" requires explicit package name...' But it is not giving any error. It gives the output as '3'. Why so? As far as I know, if we use strict, then we need to define the scope of the variable otherwise it gives an error. Is my understanding wrong? 回答1: $a and $b are special variables, and thus are not rising error when

use strict; behaviour not working as expected in Perl wrt $a and $b

由 旧时模样 提交于 2020-12-26 07:54:22
问题 I have written a sample perl code: use strict; use warnings; $a=1; $b=2; if($b==2) { $a=3; } print $a; Ideally, when I run this code, it should give an error as 'Global symbol "$a" requires explicit package name...' But it is not giving any error. It gives the output as '3'. Why so? As far as I know, if we use strict, then we need to define the scope of the variable otherwise it gives an error. Is my understanding wrong? 回答1: $a and $b are special variables, and thus are not rising error when

Error installing perl using perlbrew on Big Sur

由 夙愿已清 提交于 2020-12-26 06:55:16
问题 I'm trying to install perl version 5.33.4 in my macOS environment using perlbrew. I cannot comprehend why it fails during installation. I started installing perlbrew using \curl -L https://install.perlbrew.pl | bash , then I added in my zshenv this line: source ~/perl5/perlbrew/etc/bashrc and started installing perl with perlbrew install perl-5.33.4 command. I tried also with different perl versions, but the problem is the same. This is the logged error: # Failed test 20 - array should
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