Shell Programming and Scripting

http://www.google.co.uk
http://www.google.com
https://www.google.co.uk
https://www.google.com
ftp://
file:///somefile/on/a/server/accessed/from/browser/file.txt

/^(?:(?:https?|ftp|http):\/\/)(?:\S+(?::\S*)?@)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?$/i

file://c:/a/b/c.txt
file:///some/file/on/a/unix/a.txt

NAME
    Regexp::Common::URI -- provide patterns for URIs.

SYNOPSIS
        use Regexp::Common qw /URI/;

        while (<>) {
            /$RE{URI}{HTTP}/       and  print "Contains an HTTP URI.\n";
        }

DESCRIPTION
    Patterns for the following URIs are supported: fax, file, FTP, gopher,
    HTTP, news, NTTP, pop, prospero, tel, telnet, tv and WAIS. Each is
    documented in the Regexp::Common::URI::scheme, manual page, for the
    appropriate scheme (in lowercase), except for NNTP URIs which are found in
    Regexp::Common::URI::news.

http://www.google.com
https://www.google.com
ftp://server.com/file/a.txt
file:///some/path/to/file.txt

#!/usr/bin/env bash

# @(#) s1       Demonstrate URI validation with perl module.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
em() { pe "$*" >&2 ; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C perl

FILE=${1-data1}

pl " Sample perl code, callable at command line:"
cat p1

pl " Input data file $FILE:"
cat $FILE

pl " Results:"
./p1 data1

exit 0

$ ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 3.16.0-4-amd64, x86_64
Distribution        : Debian 8.6 (jessie) 
bash GNU bash 4.3.30
perl 5.20.2

-----
 Sample perl code, callable at command line:
#!/usr/bin/env perl

# @(#) p1       Demonstrate URI validation module.

use strict;
use warnings;
use Regexp::Common qw /URI/;

# Extended pattern to match HTTPS.
my($https) = qr($RE{URI}{HTTP}{-scheme=>qr/https/});

# Convert to lowercase for match, but retain original for display.
my($uri);
while (<>) {
  chomp;
  $uri = $_;
  $_ = lc;
  /$https/ and print "Contains an HTTPS URI: $uri\n";
  /$RE{URI}{HTTP}/ and print "Contains an HTTP URI: $uri\n";
  /$RE{URI}{file}/ and print "Contains a  FILE URI: $uri\n";
  /$RE{URI}{FTP}/ and print "Contains an FTP URI: $uri\n";
}

exit(0);

-----
 Input data file data1:
http://www.google.com
https://www.google.com
http
HTTP
ftp://server.com/file/a.txt
faux://bad
file:///some/path/to/file.txt
phonehome://///something
helloworld://www.unix.com
https://www.unix.com
https://www.unix.com
https://www.unix.com/shell-programming-and-scripting/268589-regex-urls-files.html

-----
 Results:
Contains an HTTP URI: http://www.google.com
Contains an HTTPS URI: https://www.google.com
Contains an FTP URI: ftp://server.com/file/a.txt
Contains a  FILE URI: file:///some/path/to/file.txt
Contains an HTTP URI: https://www.unix.com
Contains an HTTP URI: https://www.unix.com
Contains an HTTP URI: https://www.unix.com/shell-programming-and-scripting/268589-regex-urls-files.html