Perl:perl is used in conjunction with regular expressions, loops, and shell commands.

There is an instance where Perl reads a pattern from the configuration file, which has a combination of shell commands to get current information about Linux, and the entire pattern is complete after getting the return value of the shell command.

After Perl acquires the pattern, it executes the shell combination and replaces the result with the shell command characters from the string. If there is more than one shell command. Loops are also required to extract the execution and substitution using regular expressions respectively. For example:

#!/usr/bin/perl UseStrict; Usewarnings;$_='today\ ' s Date is: $ (date + "%y-%m-%d") $ (date + "%y-%m-%d")';my $result; while(M/\$\ ([^\)]*)/g) {$result=`$1`; Chomp($rseult); $_=~s/\$\ ([^\)]*\)/$result/;}Print;

Perl:perl is used in conjunction with regular expressions, loops, and shell commands.