[Perl] using the Geopt::long module to receive command-line arguments

There are two ways in which a Perl program needs to handle user input parameters:

The first method is to use the @argv array

The second approach is to call the Getopt::long module, which is convenient and powerful. This article mainly introduces this method.

Getopt::long invocation instance in Perl:

#!/usr/bin/perluse getopt::long;my ($verbose, $monitor, $debug, $test);
My @libs = ();
My%flags = ();

' monitor! '   
' Debug:i '    
' Test|t=s '   
' Lib=s '      
   ' Flag=s '     
);

Print "verbose= $verbose, monitor= $monitor, debug= $debug, test= $test, [email protected]\n];
while (My ($k, $v) =each%flags) {
  print "$k = $v \ n";
}

Code Explanation:

1. ' verbose+ ': ' + ' means that you do not need the option followed by an argument, and each time you use this option verbose the variable automatically plus 1.

For example:-verbose-verbose appears in the command line 2 times, verbose value becomes 2.

2. ' monitor! ': "!" Indicates that the option does not need to be followed by parameters and can be used directly (-monitor). At this point the default value for more is 1.

Often used to set open and close a feature,-monitor means open,-nomonitor indicates off.

3. ' Debug:i ': ': ' indicates that the argument followed by this option can be 0 or a null character

4. ' test|t=s ': ' | ' means that the option can be abbreviated, such as-test can be shortened to-t

"=" indicates that the option must be followed by a parameter

5. ' lib=s ' + \ @libs: If libs is an array variable, this option can occur more than once, and the period value is stored in arrays.

6. ' flag=s ': ' = ' indicates that the option is followed by a parameter of type string (s), Integer (i), or floating-point number (f).

7. ' Flag=s ' + \%flags: If Flags is hashed, the parameter of this option requires a key-value pair (Key=value) whose value is stored in the hash.

Note: When parameters match, the case is ignored, and its options can be abbreviated (the only shortest string, such as the first letter:-M for-more)

Getopt Program Execution Method:

Assuming the above code is saved in the test.pl file, chmod +x test.pl.

$./test.pl--verbose--verbose-v--monitor--lib= '/lib '-l '/lib64 '--f a=1--flag b=2  --debug 2-t Random

Executing the above code, you can get the following result:

Verbose=3, Monitor=1, debug=2, Test=random, libs=/lib/lib64a=>1b=>2

Getopt::long Module Pass Parameters:

1. Parameter type: S is a string, I is an integer, and F is a floating-point number

2. Variable type: $ is a normal variable, @ is an array, and% is a hash

[Perl] using the Geopt::long module to receive command-line arguments