[SOLVED] What kind of search routine do I need?

Dafydd · 12-24-2012, 04:55 PM

If I have data writen to a file on my server that takes this flavor:

Code:

12/25/2012, Tx, Houston, SingersName, SingersWebSite, VenueWebSite
2/20/2013, Ar, Little Rock, SingersName, SingersWebSite, VenueWebSite
10/15/2012, Ok Tulsa, SingersName, SingersWebSite, VenueWebSite
2/25/2012, Tx, Dallas, SingersName, SingersWebSite, VenueWebSite
6/25/2012, Or, Portland, SingersName, SingersWebSite, VenueWebSite

And I want to search to see if an event is happening, will it be as simple as:

Code:

readline
	if element(1) == request(1) and
			if element(2) == request(2) and
				if element(3) == request(3) then
		print all 6 elements to screen
	else
		read next line

I am more interested in what kind of search this would be. Seems PHP more that enough to take care of my needs. Especially on 'PHP.net'.

AnanthaP · 12-24-2012, 08:37 PM

Practically, I am not sure whether ultimate end users would key in exact and full dates (they might want a range) or city names. An option would be to have the user select the date (or date range) on line, let the user choose form the drop down list of states (static) and then based on it, cities with open performances.

Secondly, it is generally believed (though I have no proof) that using search tools would be more eficient compared to custom built nested-ifs. I mean once you get the parameters, a sed, grep or awk should do.

OK

Dafydd · 12-24-2012, 10:09 PM

Quote:

Originally Posted by AnanthaP

Practically, I am not sure whether ultimate end users would key in exact and full dates (they might want a range) or city names. An option would be to have the user select the date (or date range) on line, let the user choose form the drop down list of states (static) and then based on it, cities with open performances.

That is exactly what will happen. I posted the code that wrote that data in another thread. Just need to finish it.

Quote:

Secondly, it is generally believed (though I have no proof) that using search tools would be more eficient compared to custom built nested-ifs. I mean once you get the parameters, a sed, grep or awk should do. OK

Interesting. This would make things so much simpler. Will 'grep' et al be available on linux based servers?

Thanks for this new insight.
Dave

David the H. · 12-25-2012, 07:00 AM

grep, sed, and awk are defined in the POSIX standard as core system tools, so yes, some version should be available on all *nix-based systems.

Almost all Linux distributions use the GNU versions, which have many useful extensions, but the posix syntax should be pretty much universally portable.

Dafydd · 12-26-2012, 02:20 PM

I searched for an example using either 'system(grep)' or 'exec(grep)', found nothing. Did find some alternitive sugguestions. This is one of them.

This is the code adapted for an example of 'strpos' found here: http://www.ehow.com/how_8481508_stri...#ixzz2GBM2EfuW

Not working as expected.

Code:

<?php
	$file = fopen("WhereAmIPlaying", "r") or exit("Unable to open file!");
	$searchPattern = "01/31/2013, TX, Austin";

	while(!feof($file))
	  {
	 	 $stringToSearch = fgets($file);
				printf('%s', $stringToSearch); // test for data
				printf('%s', $searchPattern);  // test for data
    		$locationOfString = strpos($stringToSearch , $searchPattern );

			if($locationOfString == false) 
			{ 
				print('string not found'); 
			}
			else 
			{ 
				printf('%s', $stringToSearch); 
			}
	 }
?>

This is the content of 'WhereAmIPlaying'.

Quote:

01/04/2013, Tx, Austin, Lake Street Dive, LSD.com, WhipInn.net
01/16/2013, Tx, Huntsville, Becca Loebe, RebeccaLoebe.com, ArHouseConcerts.com
12/29/2012, Tx, Hem[steqe, Kendra Smith, KS.com, KS.net
02/08/2013, Al, Atlanta, Becca Loebe, RebeccaLoebe.com, EddoesAtoc/cp,
01/31/2013, Tx, Austin, Sara Hickman, Sara.com, Sara.net
01/31/2013, TX, Austin, Raina Rose, RainaRose.com, CactusCafe.edu
01/31/2013, TX, Austin, Carrie Elkin, carrieelkin.com, WyldWood.com

This is what is printed to my screen.

Quote:

01/04/2013, Tx, Austin, Lake Street Dive, LSD.com, WhipInn.net 01/31/2013, TX, Austinstring not found01/16/2013, Tx, Huntsville, Becca Loebe, RebeccaLoebe.com, ArHouseConcerts.com 01/31/2013, TX, Austinstring not found12/29/2012, Tx, Hem[steqe, Kendra Smith, KS.com, KS.net 01/31/2013, TX, Austinstring not found02/08/2013, Al, Atlanta, Becca Loebe, RebeccaLoebe.com, EddoesAtoc/cp, 01/31/2013, TX, Austinstring not found01/31/2013, Tx, Austin, Sara Hickman, Sara.com, Sara.net 01/31/2013, TX, Austinstring not found01/31/2013, TX, Austin, Raina Rose, RainaRose.com, CactusCafe.edu 01/31/2013, TX, Austinstring not found01/31/2013, TX, Austin, Carrie Elkin, carrieelkin.com, WyldWood.com 01/31/2013, TX, Austinstring not found01/31/2013, TX, Austinstring not found

danielbmartin · 12-26-2012, 05:21 PM

Code:

$searchPattern = "01/31/2013, TX, Austin";

Will your search always be the first three comma-delimited data items, as shown in your example?
Or, do you want to search on any number of data items, in any order?

Daniel B. Martin

ntubski · 12-26-2012, 07:32 PM

Quote:

Originally Posted by Dafydd

This is the code adapted for an example of 'strpos' found here: http://www.ehow.com/how_8481508_stri...#ixzz2GBM2EfuW

Well, ehow is confirmed as a horrible site to get information from. First off, obviously you'll want to add newlines to the output, because it's completely unreadable. Now, let's look at the official PHP manual page for strpos(), scroll down to the big red Warning box:

Quote:

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

If you follow the link to Booleans section you can see that 0 gets converted into FALSE, so if you find match at the beginning of the string, $locationOfString will == FALSE (but not === FALSE).

Okay, so that should tell how to use strpos() correctly, but if you look at what it does: "Find the ... first occurrence of a substring ..." you might realize that it's doing more than you want. Specifically, you only want to match the beginning of the line, not search the entire string. For this task you should use strncmp().

Dafydd · 12-26-2012, 07:35 PM

Quote:

Originally Posted by danielbmartin

Code:

$searchPattern = "01/31/2013, TX, Austin";

Will your search always be the first three comma-delimited data items, as shown in your example?

Yes.

Quote:

Or, do you want to search on any number of data items, in any order?
Daniel B. Martin

No.

danielbmartin · 12-26-2012, 09:12 PM

Could you use something as simple as this?

InFile ...

Code:

01/04/2013, Tx, Austin, Lake Street Dive, LSD.com, WhipInn.net
01/16/2013, Tx, Huntsville, Becca Loebe, RebeccaLoebe.com, ArHouseConcerts.com
12/29/2012, Tx, Hem[steqe, Kendra Smith, KS.com, KS.net
02/08/2013, Al, Atlanta, Becca Loebe, RebeccaLoebe.com, EddoesAtoc/cp,
01/31/2013, Tx, Austin, Sara Hickman, Sara.com, Sara.net
01/31/2013, TX, Austin, Raina Rose, RainaRose.com, CactusCafe.edu
01/31/2013, TX, Austin, Carrie Elkin, carrieelkin.com, WyldWood.com

Code ...

Code:

SP="01/31/2013, TX, Austin"  # SP = Search Pattern
grep ^"$SP" $InFile

Result ...

Code:

01/31/2013, TX, Austin, Raina Rose, RainaRose.com, CactusCafe.edu
01/31/2013, TX, Austin, Carrie Elkin, carrieelkin.com, WyldWood.com

Daniel B. Martin

Dafydd · 12-26-2012, 10:59 PM

Grep would be excellent.

I want to do this on my website. Have clients log in and enter the date state and city they are visiting and get back a list of musicians that are playing on the date they will be there.

If 'grep' is a core unit in Linux, how do I call grep from inside a html/php program on my host server that will read the data file?

danielbmartin · 12-27-2012, 07:14 AM

Quote:

Originally Posted by Dafydd

Grep would be excellent.

I want to do this on my website. Have clients log in and enter the date state and city they are visiting and get back a list of musicians that are playing on the date they will be there.

If 'grep' is a core unit in Linux, how do I call grep from inside a html/php program on my host server that will read the data file?

Oh wow, I am way over my depth here. I suggested grep and gave an example but I know almost zero about html or php or servers. Let's hope one of the LQ Gurus steps forward to address those topics.

Daniel B. Martin

danielbmartin · 12-27-2012, 05:50 PM

Just for fun I implemented the search as a standalone program. You might like to play with it and adapt it to the GUI in your web site.

Input file ...

Code:

01/04/2013, TX, Austin, Lake Street Dive, LSD.com, WhipInn.net
01/16/2013, TX, Huntsville, Becca Loebe, RebeccaLoebe.com, ArHouseConcerts.com
12/29/2012, TX, Hempstead, Kendra Smith, KS.com, KS.net
02/08/2013, GA, Atlanta, Becca Loebe, RebeccaLoebe.com, EddoesAtoc/cp,
01/31/2013, TX, Austin, Sara Hickman, Sara.com, Sara.net
01/31/2013, TX, Austin, Raina Rose, RainaRose.com, CactusCafe.edu
01/31/2013, TX, Austin, Carrie Elkin, carrieelkin.com, WyldWood.com

The program, in its entirety ...

Code:

#!/bin/bash
#  Daniel B. Martin   Dec12
#
#  To execute this program, launch a terminal session and enter:
#  bash /home/daniel/Desktop/LQfiles/dbm568.bin
#
#  This program inspired by
#  http://www.linuxquestions.org/questions/programming-9/
#    what-kind-of-search-routine-do-i-need-4175442825/
 
Path='/home/daniel/Desktop/LQfiles/dbm568'
InFile=$Path'inp.txt'
  CDLs=$Path'cdls.txt'

# Construct a list of concert dates/locations.
# Format of date field is mm/dd/yyyy
cut -d\, -f1-3 $InFile         \
|sort -n -k1.7 -k1.1 -k1.4 -u  \
|nl -s" "                      \
> $CDLs                          

# Solicit user input: select date/location.
echo; echo "Concert dates and locations:"; cat $CDLs
echo
echo "Please enter the NUMBER which identifies the date/location of interest."
read CDLnum

# Establish the Search Pattern.
SP=$(sed $CDLnum'q;d' $CDLs  \
|sed 's/^[ \t]*//'           \
|cut -d" " -f2-) 

# Check the calendar for matches on the Search Pattern.
echo; echo "Concert dates matching" $SP
grep -i ^"$SP" $InFile  # Check the calendar for matches
echo

exit

I didn't bother with niceties such as range-checking the user's numerical input. No need for that if your GUI invites the user to make a selection from a pull-down menu.

Daniel B. Martin

Dafydd · 12-29-2012, 05:08 PM

This code will select the desired date row and present it to the screen.

Code:

<?php
	$file = fopen("WhereAmIPlaying", "r") or exit("Unable to open file!");
	$searchPattern = '01/31/2013, TX, Austin';

	while(!feof($file))
	  {
	 	 $stringToSearch = fgets($file);
//				printf('%s', $stringToSearch); // test for data
//				printf('%s', $searchPattern);  // test for data
    		$locationOfString = stripos($stringToSearch , $searchPattern);

			if($locationOfString !== false) 
			{ 
				printf('%s', $stringToSearch);
				echo "<br>";  
			}
	 }
	fclose($file);
?>

You can view it in action here.
Marking this thread solved.