MoonPoint Support Weblog

OnlineWebCheck HTML Validator

I've been using the Markup Validation Service provided by the World Wide Web Consortium (W3C) to check for errors in the HTML code for webpages on this site, but recently came across another such free service, the Free HTML & CSS Validation Service at OnlineWebCheck.com. Like the W3C service, you can provide a URL for your website to be analyzed for HTML errors. The service will display any errors found on a submitted page and warnings for page elements that aren't errors, but which may deserve closer scrutiny. The online service is free and allows you to check URLs one-by-one. The service uses CSE HTML Validator Pro, which is software that runs on Microsoft Windows systems, or Linux and Mac OSX with Wine. There is a free version of that software available for download as well as paid versions with more features - see Compare CSE HTML Validator Editions. I haven't yet tried that software on a Microsoft Windows system yet, though, but have only used the online validation service.

I found the service yesterday when the W3C service wasn't responding. One warning I received for a submitted page was for the lack of a language specification within the <HTML> start tag. The warning was:

The natural primary language is not specified. It is highly recommended that the "lang" and/or "xml:lang" (for XHTML) attributes be used with the "html" element to specify the primary language. For example, add the attribute lang="en" for English or lang="fr" for French. Specifying the language assists braille translation software, speech synthesizers, translation software, and has other benefits.

<html>

I had been including the following within the <head> section:

<meta name="language" content="english">

The OnlneWebCheck.com validator noted in regards to it, though:

Remove this meta tag and use the "lang" attribute on the "html" element if trying to specify the document's language, or use a "dcterms.language" meta tag instead. Furthermore, "language" is not a recognized metadata name. Visit http://www.w3.org/TR/html5/document-metadata.html#standard-metadata-names and http://wiki.whatwg.org/wiki/MetaExtensions for more information.

<meta name="language" content="english">

Though the W3C validation service had never issued any warnings nor errors related to the lack of inclusion of the language attribute within the <HTML> tag or use of the meta tag, at the W3C site at Specifying the language of content: the lang attribute webpage, I found:

Language information specified via the lang attribute may be used by a user agent to control rendering in a variety of ways. Some situations where author-supplied language information may be helpful include:

Assisting search engines

Assisting speech synthesizers

Helping a user agent select glyph variants for high quality typography

Helping a user agent choose a set of quotation marks

Helping a user agent make decisions about hyphenation, ligatures, and spacing

Assisting spell checkers and grammar checkers

The recommendation made for assisting search engines and browsers to determine the language for webpages is to include the language attribute within the <html> tag as shown below:

<html lang="en">
...
</html>

Or for XHTML:

<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
...
</html>

So, I decided to modify the template that I use for pages to include the language attribute within the <html> tag, i.e., to use <html lang="en">, and to include the attribute within the <html> tag for Blosxom's head.html file.

If a page is in another language than English, the appropriate code can be chosen from the ISO 639-1 two-letter language codes. ISO 639-1 defines abbreviations for languages. In HTML and XHTML they can be used in the lang and xml:lang attributes.

[/network/web/design] permanent link

Sat, Mar 29, 2014 4:24 pm

Google Analytics Add-on for Google Sheets

If you use Google Analytics, for monitoring your website, Google now provides an add-on for Google Sheets, which is Google's equivalent to Microsoft Excel, available through Google Docs, that allows you to incorporate Google Analytics data within a Google Sheets worksheet.

[ More Info ]

[/network/web/services/google] permanent link

Sat, Mar 29, 2014 10:19 am

Cell Padding in a Table

There are multiple ways to add padding around text within cells in a table. Specifying

<table
cellpadding="ypx">

with y representing the number of pixels of padding will add padding to the left, right, top, and bottom of the text. If you only wish to have additional padding at the left and right of the text, you can do so by CSS, e.g.:

<style type="text/css">
   .padded {padding-left: 10px; padding-right: 10px;}
</style>

You can then apply the class "padded" to each td in the table.

[ More Info ]

[/network/web/design] permanent link

Fri, Mar 28, 2014 10:12 pm

Problem with Blosxom calendar cache

I use the Calendar Plugin for Blosxom on this site. When I checked the site with the Xenu Link Sleuth tool, which reveals broken links, today I found it reporting errors for urls with "//" in the directory path in the URL. It took me a few minutes to realize that the errors were due to the calendar displayed for the blog that points to prior entries. When I looked at the URLs for various days on this month's calendar, I saw that the links were all appearing similar to the following one:

http://support.moonpoint.com/blog/blosxom/2014/03//RS=%5EADAZpNNfKrcEOr1DFixlJAHJ_euLow-/2014/03/04/2014/03/2014/03/01/

They had "RS=" and "euLow-" followed by repetitions of the year and month in the URL. I knew that the links had been appearng normally, so I suspected the problem was caused when I posted an entry this morning. Sometimes when I've worked on something previously, but not yet posted it, I will change the time on the file associated with the entry to point to the date and time I worked on it or when I edit an entry I may set its time stamp to the original date and time after I've finished editing it. I had done that this morning, so I suspected there was a problem with the calendar's cache file, .calendar.cache, which is located in the Blosxom plugins state directory, plugins/state. The file can be deleted; it will be recreated automatically when the Blosxom blog is viewed again. I deleted the file and refreshed the page in the browser with which I was viewing the site and all of the links for the calendar then appeared normally.

[/network/web/blogging/blosxom] permanent link

Fri, Mar 28, 2014 9:22 pm

Xenu Link Sleuth

When I checked the error log for this site this morning, I noticed an entry pointing to a nonexistent file on the site, which led me to check the Apache CustomLog file to look for information on why someone might have followed a link to a file that never existed on the site. I didn't discover the source of the incorrect link, but in the process of checking for that incorrect link I found a very useful tool, Xenu Link Sleuth, that revealed a signficant problem with the site due to a change I made this morning and pointed out broken internal links on the site.

[ More Info ]

[/network/web/tools] permanent link

Fri, Mar 28, 2014 10:46 am

Determing the NTP servers in use on a Mac OS X system

If you need to know the Network Time Protocl (NTP) server in use on a Mac OS X system you can use the command

systemsetup -getnetworktimeserver

or you can look at the contents of the /etc/ntp/conf file.

$ systemsetup -getnetworktimeserver
Network Time Server: ntp.example.com
$ cat /etc/ntp.conf
server ntp.example.com minpoll 12 maxpoll 17
server time.apple.com

The minpoll and maxpoll values specify the minimum and maximum poll intervals for querying the time server as a power of 2 in seconds. So, for the example above, where the time server is ntp.example.com, the minimum interval is 2 to the power of 12 or 4,096 seconds, which is a little over an hour (1.14 hours). The minimum interval defaults to 6, which equates to 2 to the power of 6, which is 64 seconds. The maximum interval defaults to 10, i.e. 2 raised to the power 10, which is 1,024 seconds. The upper limit for the value is 17, which is 36.4 hours. A secondary time server is also shown in the example above. The secondary time server could be used when the primary one is unavailable.

[/os/os-x] permanent link

Wed, Mar 26, 2014 9:21 pm

Green border around Google Sheets cell

If a green border appears unexpectedly around a cell in a Google Sheets spreadsheet, then the worksheet is likely open elsewhere. If you've shared the spreadsheet, someone with whom you have shared it may have it open or you may have it open on another system or even in another tab within your browser. In that case the cell that is currently selected in the other open instance of the worksheet will be highlighted by a green border. At the top of the worksheet you will also see the number of other instances of the open worksheet. If it is open in just one other place you will see "1 other viewer" at the top right of the worksheet next to a green square.

If you move the cursor over the cell with the green border, you will see the name of the other user displayed, or your own logged in name, if you have the worksheet open multiple times. You can also put the cursor over the green squares at the top right area above the spreadsheet to see those names. If the worksheet was open more than twice, e.g., if it was open 3 times, you would see additional green boxes corresponding to the number of other open instances of it.

[/network/web/services/google] permanent link

Tue, Mar 25, 2014 9:13 pm

Not enough free disk space for Entourage

If Entourage display the message "Your hard disk is full. The Entrourage database requires additional free space. Entourage will now quit so you can make more space available on your hard disk by moving or deleting files.", if you store a lot of email one area where you may be able to free disk space is in old identities or backups for an identity beneath ~/Documents/Microsoft User Data

[More Info ]

[/os/os-x/software/office] permanent link

Mon, Mar 24, 2014 8:17 am

Attempted SQL injection attack

When I checked the webserver's error log file this morning, I noticed the following two entries related to the IP address 221.11.108.10:

[Mon Mar 24 08:15:07 2014] [error] [client 221.11.108.10] File does not exist: / home/jdoe/public_html/ctscms
[Mon Mar 24 08:15:12 2014] [error] [client 221.11.108.10] File does not exist: /home/jdoe/public_html/plus, referer: http://support.moonpoint.com/plus/search.php?keyword=as&typeArr[111%3D@`\\'`)+and+(SELECT+1+FROM+(select+count(*),concat(floor(rand(0)*2),(substring((select+CONCAT(0x7c,userid,0x7c,pwd)+from+`%23@__admin`+limit+0,1),1,62)))a+from+information_schema.tables+group+by+a)b)%23@`\\'`+]=a

There is no ctscms file nor directory, nor do I use a search.php file, nor even have a directory named plus on this web site, so the queries seemed suspicious.

Performing a Google search on the attempted query to search.php, which appears to be an SQL query, I found links to a number of sites in the Chinese language. E.g., dedecms plus / search.php latest injection vulnerability (translated to English).

The query I saw in the Apache error log appeared to be an SQL injection attack. In Arrays in requests, PHP and DedeCMS, an InfoSec Handlers Diary Blog entry, I found the following in relation to an SQL injection attack used against /plus/download.php, which is a PHP script associated with the DedeCMS Content Management System (CMS):

And this definitely looks malicious. After a bit of research, it turned out that this is an attack against a known vulnerability in the DedeCMS, a CMS written in PHP that appears to be popular in Asia. This CMS has a pretty nasty SQL injection vulnerability that can be exploited with the request shown above.

So I blocked any further access to the server hosting this site from that IP address using a route reject command.

# route add 221.11.108.10 reject
[root@frostdragon ~]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
221.11.108.10   -               255.255.255.255 !H    0      -        0 -
171.216.29.9    -               255.255.255.255 !H    0      -        0 -

The 221.11.108.10 IP address is allocated to an entity in China. I blocked another Chinese IP address, 171.216.29.9 two days ago.

The Arrays in requests, PHP and DedeCMS blog entry indicated the attacker discussed in that article was using a script that identified itself with a user agent string of WinHttp.WinHttpRequest:

Additionally, as you can see in the log at the top, the User Agent string has been set to WinHttp.WinHttpRequest, which indicates that this request was created by a script or an attack tool executed on a Windows machine.

When I checked the Apache CustomLog to see what user agent string was submitted with the queries to this site, I saw it was "Googlebot/2.1", so the attacker appears to be using an updated script. that misidentifies itself as Googlebot. The Internet Storm Center blog entry was posted 6 months ago and discusses a log entry from September 5, 2013. The log entry posted in that article shows a source IP address of 10.10.10.10, which is a private IP address substituted in the article for the actual IP address from which the attack originated.

I saw the following in my log:

221.11.108.10 - - [24/Mar/2014:08:15:07 -0400] "GET /ctscms/ HTTP/1.1" 404 291 "
-" "Googlebot/2.1 (+http://www.google.com/bot.html)"
221.11.108.10 - - [24/Mar/2014:08:15:12 -0400] "GET /plus/search.php?keyword=as&
typeArr[111%3D@`\\'`)+and+(SELECT+1+FROM+(select+count(*),concat(floor(rand(0)*2
),(substring((select+CONCAT(0x7c,userid,0x7c,pwd)+from+`%23@__admin`+limit+0,1),
1,62)))a+from+information_schema.tables+group+by+a)b)%23@`\\'`+]=a HTTP/1.1" 404
 299 "http://support.moonpoint.com/plus/search.php?keyword=as&typeArr[111%3D@`\\
'`)+and+(SELECT+1+FROM+(select+count(*),concat(floor(rand(0)*2),(substring((sele
ct+CONCAT(0x7c,userid,0x7c,pwd)+from+`%23@__admin`+limit+0,1),1,62)))a+from+info
rmation_schema.tables+group+by+a)b)%23@`\\'`+]=a" "Googlebot/2.1 (+http://www.go
ogle.com/bot.html)Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, a
pplication/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-power
point, application/msword, */*"

References:

Stopping an Attacker with the Route Reject Command
MoonPoint Support
Date: April 15, 2007
Arrays in requests, PHP and DedeCMS
Internet Storm Center
By: Bojan, ISC Handler

[/security/attacks] permanent link

Sun, Mar 23, 2014 2:08 pm

Julian date in spreadsheets

The ordinal date, i.e., the day of the year, is a number that ranges from 1 for January 1 through 365 or 366 for December 31, depending if the year is a leap year. The ordinal date is also referred to as the "Julian date", though in astronomy "Julian date" is not the ordinal date, but a serial date system starting on January 1, 4713 B.C.E.

If you wish to display the current ordinal date in a spreadsheet, such as a Microsoft Excel or a Google Sheets worksheet you can use the formula below:

=TEXT(TODAY() ,"yyyy")&TEXT((TODAY() -DATEVALUE("1/1/"&TEXT(TODAY(),"yy"))+1),"000")

That formula will insert the current day in Julian format with a four-digit year. E.g. for March 23, 2014, it would result in 2014082 appearing in the cell where the forumla is used, since March 23, 2014 is the 82^nd day of 2014. If you just wish to display the day of the year and not the year, you can use the formula below:

=TEXT((TODAY() -DATEVALUE("1/1/"&TEXT(TODAY(),"yy"))+1),"000")

That forumula will display 082 in the cell in which the formula is used.

References:

Insert Julian dates
Support - Office.com

[/os/windows/office/excel] permanent link

Sun, Mar 23, 2014 1:31 pm

W3C Validation

The World Wide Web Consortium (W3C) is an international standards organization for the World Wide Web (WWW). Among the services offered by the W3C are a Markup Validation Service a Link Checker, a CSS Validation Service, and RSS Feed Validation Service. The services are free.

The markup validation service allows you to submit a URL for a webpage to be checked by the service or to upload an HTML file to be checked for incorrect HTML code. If the code in a webpage is incorrect, you may not see the results you expect for the webpage when it is displayed in a browser or it may display incorrectly in some browsers used by visitors to the page. The W3C tool will notify you of the types of errors on the page and the line numbers on which they are found. You can match those lines numbers with the appropriate lines in the code in browsers that allow you to view the source code of a page.

You can provide a URL to the link checker tool and it will determine if any of the links on the webpage are invalid.

The CSS validation service allows you to check the validity of Cascading Style Sheets (CSS) used on webpages to control the appearance and formatting of the pages. You can provide a URL for a CSS or upload a CSS file to be verified.

The W3C Feed Validation Service will check the syntax of Atom or RSS feeds. E.g., if you use RSS to publish updated information on blog entries, you can provide the URL for the index.rss file on your site.

The W3C provides other tools as well at Quality Assurance Tools. All of the software developed at the W3C is Open Source / Free software, which means that you can use the software for free and download the code, if you wish. You can also modify the code to suit your own purposes, if you wish.

There is also a paid W3C Validator Suite™, if you wish to have the W3C validate an entire site automatically rather than you validating pages individually.

Note: the W3C validation services can't check pages that require authentication, but can only check pages that are accessible from the Internet without passwords or files that you upload to be checked.

[/network/web/design] permanent link

Sat, Mar 22, 2014 10:49 pm

Blocking Internet access except for virus scanning sites

After a system became infected with malware, I disconnected its network cable then added rules to the firewall separating it from the Internet to block all Internet access except for DNS access to its designated DNS server provided by the user's ISP. I then granted access to the VirusTotal IP addresses on all ports. VirusTotal is a website belonging to Google that will allow you to scan files you upload to it with multiple antivirus programs to determine if they may be malware.

Name	IP Addresses
virustotal.com	216.239.32.21 216.239.34.21 216.239.36.21 216.239.38.21
www.virustotal.com	74.125.34.46

After implementing the firewall rules, I reconnected the network cable to the system.

Since accessing http://virustotal.com redirects one to http://www.virustotal.com, I wasn't able to access the VirusTotal website until I added the IP address 74.125.34.4 to the list of destination IP addresses the infected system was allowed to access through the firewall. Even though I could then access the site's webapge and select a file to upload, I was unable to actually upload a file that I wanted to check for malware.

So I then added the IP address for the Jotti's malware scan website to the permitted outbound access list for the infected system. I was able to access it with a web browser on the system and upload a suspect file to have it scanned by the 22 antivirus programs the site currently uses to scan uploaded files.

Name	IP Addresses
virusscan.jotti.org	209.160.72.83

[/security/scans] permanent link

Sat, Mar 22, 2014 5:42 pm

Blocking access from 171.216.29.98

I noticed entries in Apache's error log today associated with IP address 171.216.29.98:

[Sat Mar 22 15:23:58 2014] [error] [client 171.216.29.98] PHP Notice: Undefined index: HTTP_USER_AGENT in /home/jdoe/public_html/index.php on line 39 [Sat Mar 22 15:23:58 2014] [error] [client 171.216.29.98] PHP Notice: Undefined index: HTTP_USER_AGENT in /home/jdoe/public_html/index.php on line 46 [Sat Mar 22 15:23:58 2014] [error] [client 171.216.29.98] attempt to invoke directory as script: /home/jdoe/public_html/blog/

The error was occurring because of PHP code in the file that checks the value for HTTP_USER_AGENT.

I found that the IP address, which is allocated to a system in China, is listed at the Stop Forum Spam site as being associated with someone trying to post spam into forums today - see 171.216.29.98. And when I checked Apache's CustomLog to check the user agent for the browser the user or software program running at the site might be using to identify itself, I found that the log entries indicated that it wasn't providing user agent information, which browsers and web crawlers normally provide. The log also showed that other than that one file at the site's document root, the user or program accessing the site only queried a directory that has "forums" as part of the path. I have blog entries posted on forum software, so that may have prompted the visit to the site from that IP address, if the person or program is looking for sites where he or it can post forum spam.

I checked the "reputation" of the IP address at other sites that provide information on whether an IP address has been noted to be associated with malicous activity and found the following:

Site: WatchGuard Reputation Authority
Rating: Bad
Reputation Score: 95/100
Comment: The score indicates the overall ReputationAuthority reputation score, including the name and location of the ISP (Internet Service Provier), for the specified address. A score of 0-50 indicates a good to neutral reputation. 51-100 indicates that threats have been detected recently from the address and the reputation has been degraded.
Site: Barracuda Reputation
Reputation: Poor
Comment:
Site: McAfee Trusted Source
Reputation: Unrated
Comment:
Site: Check Your IP Reputation - Miracare of Mirapoint
Reputation: High Risk
Comment: This IP address is used for sending Spam on a regular basis
Site: BrightCloud Security Services URL/IP Lookup
Reputation: High Risk
Comment: Location - Chengdu, China. Spam Sources found. Webroot IP Reputation is listed as "High Risk", but lower down on the page the status assigned to the address is "Moderate Risk".

To stop any futher access to the server from that IP address, from the root account, I used the route command to reject access by the IP address.

# route add 171.216.29.9 reject

Note: the command is valid on a Linux system, but though the route command is available on a Microsoft Windows system, that operating system doesn't support the "reject" parameter.

The blocked route can be seen by issuing the route command with no parameters.

# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
171.216.29.9    -               255.255.255.255 !H    0      -        0 -

If I ever want to permit access to the server from that IP address again, I could use route del 171.216.29.9 to permit access from that address.

References:

Stopping an Attacker with the Route Reject Command
MoonPoint Support
Date: April 15, 2007

[/security/scans] permanent link

Sat, Mar 22, 2014 2:10 pm

Renamed Website Files Still Being Crawled

I've noticed in the site's error logs that files that haven't existed on the site for years are producing error entries when web crawers still attempt to access them. Apparently, elsewhere on the web that are still links pointing to the nonexistent files, which has led me to conclude that I need to create redirects for those files on the site that I move or rename, if the files have been on the site for any significant lengthh of time.

[ More Info ]

[/network/web/crawlers] permanent link

Fri, Mar 21, 2014 9:55 pm

Favicon.ico

While trying to reduce entries in the site's Apache error log, I've decided I should eliminate the many "File does not exist" error messages for favicon.ico. I often see attempts to access that file from the site's root directory, but, since there is no such file, a lot of extraneous entries appear in the error log file for it when browsers attempt to access it. Favicon is short for "favorite icon" and is also known as a "shortcut icon". Favicons were first supported in March 1999 when Microsoft released Internet Explorer 5. In December of 1999, the World Wide Web Consortium (W3C) made it a standard element in HTML 4.01 recommendation to be used with a link relation in the <head> section of an HTML document. It is now widely supported among browsers.

The original purpose of a favicon was to provide a small icon, commonly 16 x 16 pixels, that a browser would associate with a website when a user bookmarked the site. Today, browsers typically display a page's favicon in their address bar and sometimes also in the browser's history display as well as using it in association with a bookmark. Those browsers that provide a tabbed document interface (TDI) also typically display the favicon next to a page's title on a tab for the site with which the favicon is associated.

I had an icon I had used years ago, but decided I liked the crescent moon icon, I found at favicon.cc better. That site provides a tool that will allow you to create your own favicon. It also provides many free icons that you can download.

To use the icon file, you can simply place the favicon.ico in the root directory of the website where browsers can automatically locate it. Or you can place it elsewhere on the site and specify its location by inserting the following code within the head section of the HTML code for a page, substituing the relative path from the website's document root for YOUR_PATH.

<link href="/YOUR_PATH/favicon.ico" rel="icon" type="image/x-icon" />

Something like the following is also acceptable. I.e., in addition to specifying the file's location you can can also give the file a name other than favicon.ico.

<link rel="icon" href="http://example.com/myicon.ico" />

The file also does not have to be a .ico file. See the file format support section of the Wikipedia Favicon article for other image file formats that are supported by various browsers.

[/network/web/browser] permanent link

Thu, Mar 20, 2014 9:21 pm

Check marks, x marks, and checkboxes

If you need to represent a check mark, aka tick mark, or an x mark, aka cross, x, ex, exmark, and into mark, or a checkbox, aka check box, tick box, and ballot box, which someone can checkmark, on a webpage, there are a number of HTML codes that can be used to do so. The codes can be represented in decimal or hexadecimal format depending on your personal preference.

		Code
Symbol	Description	Decimal	Hexadecimal
☐	ballot box	☐	☐
☑	ballot box with check	☑	☑
☒	ballot box with x	☒	☒
✅	white heavy check mark	✅	✅
✓	check mark	✓	✓
✔	heavy check mark	✔	✔
×	mulitplication sign	×	&#x00D7
✕	large multiplication sign	✕	✕
✖	heavy multiplication sign	✖	✖
⨯	cross product, also known as Gibb's vector product	⨯	⨯
✗	ballot x	✗	✗
✘	heavy ballot x	✘	✘

If you see squares or question marks instead of the symbols, you may need an appropriate language pack installed to display the symbols.

[/network/web/html] permanent link

Wed, Mar 19, 2014 11:17 pm

AuthUserFile not allowed here

After setting up a redirect similar to the following in an .htaccess file in a directory, I found that I would get a 500 Internal Server Error with the message "The server encountered an internal error or misconfiguration and was unable to complete your request." whenever I tried to access a file in a password-protected subdirectory beneath the one in which I had created the .htaccess file to have the Apache server redirect visitors accessing an old .html file that I had replaced with a .php one.

Redirect 301 /dir1/dir2/example.html /dir1/dir2/example.php

In the Apache error log for the website, I saw the following:

[Wed Mar 19 21:05:17 2014] [alert] [client 192.168.0.10] /home/jdoe/public_html/dir1/dir2/dir3/.htaccess: AuthUserFile not allowed here, referer: http://support.moonpoint.com/dir1/dir2/example.php

That error log entry was created when I clicked on a link I had in example.php to access a file in the directory dir3, which was below the one in which example.php was located.

To allow the redirect to work, I had inserted the following code in the VirtualHost section for the website within Apache's /etc/httpd/conf/httpd.conf file.

<Directory /home/jdoe/public_html/dir1/dir2> AllowOverride FileInfo </Directory>

The .htaccess file for controlling access to the subdirectory dir1/dir2/dir3 had worked fine until I created another .htaccess file above it in dir2 for the redirect. The one for controlling access to dir3 with a username and password was similar to the following:

AuthUserFile /home/jdoe/public_html/.htpasswd-test AuthGroupFile /dev/null AuthName Testing AuthType Basic Require user test1

Because it contained AuthUserFile and AuthGroupFile, but I didn't specify AuthConfig within the <Directory> section for the virtual host in the httpd.conf file, but only FileInfo for AllowOverride, the authorization control no longer worked. When I changed the AllowOverride line to that shown below and restarted Apache with apachectl restart then both the redirect for the file in dir2 and the HTTP basic access authentication method for files in the subdirectory dir3 beneath dir2 both worked.

<Directory /home/jdoe/public_html/dir1/dir2> AllowOverride AuthConfig FileInfo </Directory>

I had forgotten that by limiting AllowOverride to just FileInfo for dir2, I was effectively nullifying any other type of overrides in any subdirectores beneath it.

References:

Apache Core Feartures
Apache HTTP Server Project

[/network/web/server/apache] permanent link

Tue, Mar 18, 2014 10:34 pm

Use netsh to determine WLAN driver version

To obtain information about the driver for the wirless interface in a Microsoft Windows system, the netsh command may be used. After issuing the command from a command prompt, you can type wlan, then show drivers to show the properites of the wireless LAN drivers on the system.

C:\Users\JDoe>netsh
netsh>wlan
netsh wlan>show drivers

Interface name: Wi-Fi

    Driver                    : Realtek RTL8188E Wireless LAN 802.11n PCI-E NIC
    Vendor                    : Realtek Semiconductor Corp.
    Provider                  : Realtek Semiconductor Corp.
    Date                      : 2/27/2013
    Version                   : 2007.10.227.2013
    INF file                  : C:\windows\INF\oem13.inf
    Files                     : 2 total
                                C:\windows\system32\DRIVERS\rtwlane.sys
                                C:\windows\system32\drivers\vwifibus.sys
    Type                      : Native Wi-Fi Driver
    Radio types supported     : 802.11n 802.11b 802.11g
    FIPS 140-2 mode supported : No
    802.11w Management Frame Protection supported : Yes
    Hosted network supported  : Yes
    Authentication and cipher supported in infrastructure mode:
                                Open            None
                                WPA2-Personal   CCMP
                                Open            WEP-40bit
                                Open            WEP-104bit
                                Open            WEP
                                WPA-Enterprise  TKIP
                                WPA-Personal    TKIP
                                WPA2-Enterprise TKIP
                                WPA2-Personal   TKIP
                                WPA-Enterprise  CCMP
                                WPA-Personal    CCMP
                                WPA2-Enterprise CCMP
                                Vendor defined  TKIP
                                Vendor defined  CCMP
                                Vendor defined  Vendor defined
                                Vendor defined  Vendor defined
                                WPA2-Enterprise Vendor defined
                                WPA2-Enterprise Vendor defined
                                Vendor defined  Vendor defined
                                Vendor defined  Vendor defined
    Authentication and cipher supported in ad-hoc mode:
                                Open            None
                                Open            WEP-40bit
                                Open            WEP-104bit
                                Open            WEP
                                WPA2-Personal   CCMP
    IHV service present       : Yes
    IHV adapter OUI           : [00 e0 4c], type: [00]
    IHV extensibility DLL path: C:\windows\system32\Rtlihvs.dll
    IHV UI extensibility ClSID: {6c2a8cca-b2a2-4d81-a3b2-4e15f445c312}
    IHV diagnostics CLSID     : {00000000-0000-0000-0000-000000000000}

netsh wlan>

Or you can issue the netsh wlan show drivers command at the command prompt to have the information shown and be immediately returned to the command prompt.

[/os/windows/commands] permanent link

Mon, Mar 17, 2014 5:48 pm

Recursively locating HTML files

To recursively locate files of a particular file type, e.g., HTML files, on a Unix, Linux, or OS X system from a command line interface, aka shell prompt, the following command can be used:

find . -name "*.html"

The subdirectory path will be included in the output along with the file names.

If you wish to have a count of the number of such files, you can use either of the two commands below:

find . -name "*.html" | grep -c . find . -name "*.html" | wc -l

Note: if you use the grep command, be sure to include the dot after the -c.

[/os/unix/commands] permanent link

Mon, Mar 17, 2014 5:30 pm

How to have Firefox forget basic access authentication credentials

If you've accessed a webpage that uses HTTP basic access authentication to prompt for a user name and password to control access to a web page within Firefox, you can have Firefox "forget" those credentials so you can enter different ones by the following two methods.

Method 1

Note: this method applies for Firefox 27 and may not apply to all other versions.

Click on Firefox at the upper, left-hand corner of the Firefox window to access its menu.
Select History.
Select Clear Recent History.
If the site was accessed within the last hour, you can leave "time range to clear" set at "Last Hour"; if not, you may need to change the value to a longer period. With Details visible, you can clear the checkmarks for all the items, except Active Logins, if you wish.
Click on the Clear Now button.

Method 2

Note: This method may work for some other browsers as well as Firefox, but won't work for Internet Explorer. An advantage to this method is it is applied to just the particular website. It doesn't cause Firefox to forget the credentials for any other websites.

With some browsers, you can specify the credentials to use to access a webpage protected by basic authenticaion by putting the userid and password in the URL for the page with http://user:pass@www.example.com, substituting a username for the site for "user" and a password that goes with that username for "pass" in the address line, e.g. http://bob:mypassword@www.example.com.

If you put http://abc@www.example.com/some-page.html in the address bar for the webpage some-page.html that is protected by the basic authentication method, then the browser can be caused to forget a valid set of credentials previously used to access that page that Firefox remembers and will normally reuse until you exit from Firefox. You will be prompted by the website for a new set of valid credentials, allowing you to enter a new user name and passwrod to access the page or cause your browser to forget the previously valid ones.

[/network/web/browser/firefox] permanent link

Sun, Mar 16, 2014 11:59 am

List of accounts on a Linux or Unix system

To see a list of accounts on a Linux or Unix system, the following command can be used:

cut -d: -f1 /etc/passwd

[/os/unix/commands] permanent link

Sun, Mar 16, 2014 9:41 am

Determining low, high, average, and median values with Google Sheets

To determine the smallest, largest, average, and median value for a column of numbers in a Google Sheets spreadsheet, the MIN, MAX, AVERAGE, and MEDIAN functions can be used.

For a column of numbers from A2 to A66, the following forumlas could be used:

Minimum:	MIN(A2:A66)
Maximum:	MAX(A2:A66)
Average:	AVERAGE(A2:A66)
Median:	MEDIAN(A2:A66)

[/network/web/services/google] permanent link

Sat, Mar 15, 2014 11:17 am

Changing the Channel Number on a NetGear CVG824G Router

Sometimes wireless network disconnections and slow data transfers can be caused by interference between multiple wireless access points, such as neighboring wireless routers using the same radio frequency channel for communications. Simply changing the channel number used for wireless communications by one of the routers may resolve the problem. For a NETGEAR® Wireless Cable Voice Gateway Model CVG824G device, the channel number can be changed using these steps.

[/hardware/network/router/netgear] permanent link

Fri, Mar 14, 2014 10:30 pm

Excel countifs function

Microsoft Excel, starting with Excel 2007, provides a function, countifs, to count the number of occurrences of some item while stipulating multiple criteria be met. The function also is available in Microsoft® Excel® 2008 for Mac. The function works like the


countif

function, but whereas countif only permits one criteria to be stipulated, countifs supports one or more criteria. The syntax for countifs is:

COUNTIFS( criteria_range1, criteria1, [criteria_range2, criteria2, ... criteria_range_n, criteria_n] )

As an example, suppose I have the following worksheet in a spreadsheet:

<>	A	B	C	D
1	Number	Project	Approved	Funded
2	38397	Alpha	2/12/14	N
3	38400	Alpha	2/7/14	Y
4	38407	Beta	3/4/14	N
5	38408	Alpha	2/25/14	N
6	38409	Epsilon	3/14/14	Y
7	38412	Gamma	3/14/14	Y
8	38413	Zeta	3/14/14	Y
9	38415	Alpha	3/14/14	N
10
11	Approved today	4
12	Approved and funded today	3

Number represents work request numbers associated with various projects. Column C has dates for when the work requests were approved with today's date being March 14, 2014. Column D indicates whether the requests have been funded with a "Y" for "yes" and a "N" for "no".

If I wished to count the number of work requests funded today, I could use the formula =COUNTIF(C2:C10,TODAY()) in cell B11. COUNTIF works because I have only one criteria. But, if I wanted to count the number that were approved and funded today, then I would need to use COUNTIFS rather than COUNTIF. I could use the formula =COUNTIFS(C2:C10,TODAY(),D2:D10,"Y") in cell B12.

[/os/windows/office/excel] permanent link

Fri, Mar 14, 2014 9:55 am

Netsh command to show available Wi-Fi networks

On a system running Microsoft Windows, you can see the available Wi-Fi networks near the system,the signal strengths, channel numbers, etc. for each from a command prompt using the command

netsh show
networks mode=Bssid

C:\Users\JDoe>netsh
netsh>wlan
netsh wlan>show networks mode=Bssid

Interface name : Wi-Fi
There are 5 networks currently visible.

SSID 1 : 558935
    Network type            : Infrastructure
    Authentication          : WPA2-Personal
    Encryption              : CCMP
    BSSID 1                 : 0c:54:a5:48:19:e5
         Signal             : 81%
         Radio type         : 802.11n
         Channel            : 1
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

SSID 2 : Haze
    Network type            : Infrastructure
    Authentication          : WPA2-Personal
    Encryption              : CCMP
    BSSID 1                 : 94:44:52:5a:54:54
         Signal             : 83%
         Radio type         : 802.11n
         Channel            : 11
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

SSID 3 : 08FX02038916
    Network type            : Infrastructure
    Authentication          : Open
    Encryption              : WEP
    BSSID 1                 : 00:18:3a:8a:01:c5
         Signal             : 49%
         Radio type         : 802.11g
         Channel            : 6
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

SSID 4 : linksys
    Network type            : Infrastructure
    Authentication          : Open
    Encryption              : None
    BSSID 1                 : 00:13:10:fa:ef:a3
         Signal             : 45%
         Radio type         : 802.11g
         Channel            : 6
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

SSID 5 : Hickox
    Network type            : Infrastructure
    Authentication          : Open
    Encryption              : WEP
    BSSID 1                 : 0c:d5:02:c5:e8:8c
         Signal             : 48%
         Radio type         : 802.11g
         Channel            : 11
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

netsh wlan>

[/os/windows/commands] permanent link

Thu, Mar 13, 2014 11:15 pm

Netsh show interfaces

The signal strength for wireless network connectivity can be checked on a Windows system from the command line using the netsh command. From a command prompt issue the command netsh and when the netsh prompt appears issue the command wlan and then show interfaces.

C:\Users\JDoe>netsh
netsh>wlan
netsh wlan>show interfaces

There is 1 interface on the system:

    Name                   : Wi-Fi
    Description            : Realtek RTL8188E Wireless LAN 802.11n PCI-E NIC
    GUID                   : d79cd37a-fe78-482b-b23e-af4953ba9f6b
    Physical address       : 48:d2:24:68:e1:aa
    State                  : connected
    SSID                   : Haze
    BSSID                  : 94:44:52:5a:54:54
    Network type           : Infrastructure
    Radio type             : 802.11n
    Authentication         : WPA2-Personal
    Cipher                 : CCMP
    Connection mode        : Auto Connect
    Channel                : 11
    Receive rate (Mbps)    : 72
    Transmit rate (Mbps)   : 72
    Signal                 : 100%
    Profile                : Haze

    Hosted network status  : Not available

netsh wlan>

The signal strength for the wireless connection is shown on the Signal line, e.g., 100% in the case above. The wireless connection is using the 802.11n wireless network standard, which is one of the 802.11 standards.

[/os/windows/commands] permanent link

Wed, Mar 12, 2014 11:40 pm

Adding "rel=nofollow" to Blosxom advanced search option for find plugin

I've noticed in the logs for the blog that search engines are trying to access pages with "?advanced_search=1" in the URL. E.g., I've seen a lot of entries similar to the following:

5.10.83.52 - - [12/Mar/2014:00:32:23 -0400] "GET /blog/blosxom/<a%20href=/<a%20h ref=/<a%20href=/2008/05/01/2008/03/2008/05/05/network/email/clients/outlook/2008 /10/network/email/sendmail/2008/07/network/email/clients/outlook/2008/05/25/2008 /12/2008/05/18/2008/05/03/index.html?advanced_search=1 HTTP/1.1" 200 12080 "-" " Mozilla/5.0 (compatible; AhrefsBot/5.0; +http://ahrefs.com/robot/)"

They seem to be getting erroneous URLs reflecting a directory structure related to dates that doesn't exist on the system. The URLs appear to be related to the find plugin, since its search option includes code for "advanced_search=1", so I've edited the Perl code for that plugin to include rel="nofollow" at the end of the URL generated for the advanced search capability.

The orignal code was:

<a href="$blosxom::url/$path_withflavour?advanced_search=1">Advanced Search</a>

The line is now:

<a href="$blosxom::url/$path_withflavour?advanced_search=1" rel="nofollow">Advanced Search</a>

Adding rel="nofollow" to a URL tells search engines, such as Google's search engine not to follow any link that includes the nofollow parameter.

The following meta tag can be included in the head section of the HTML code for a page to tell search engines not to follow any links on a page.

<meta name="robots" content="nofollow">

But there may be instances, such as this case for me, where a webpage designer wants only some links on a page not to be followed to their destination by search engines.

The attribute can also be added to individual links if you don't want to vouch for the content of the page to which the link points. E.g., adding it to links placed in comments by those commenting on a page will allow visitors to go to the linked page, but search engines that adhere to the nofollow parameter won't use the link to increase their ranking of the page to which the link points, which may discourage some comment spammers.

The rel="nofollow" option for links was developed as a way to combat link spam. In January 2005, Google, Yahoo! and MSN announced that they would support use of the "nofollow" tag as a way to deter link spam. Microsoft's MSN Spaces and Google's Blogger blogging services joined the effort to utilize the tag to discourage link spamming At that time a number of blog software providers, including Six Apart, WordPress, Blosxom, and blojsom, also joined the effort by supporting use of the tag.

References:

Use rel="nofollow" for specific links
Google Webmaster Tools
Wipedia ponders joining search engines in fight against spam
By: Michael Snow
Date: January 24, 2005

[/network/web/blogging/blosxom] permanent link

Tue, Mar 11, 2014 10:31 pm

Determining resolution from the command line on OS X

To determine the video resolution from a command line, such as a Terminal shell prompt, on an OS X system, you can use the command system_profiler SPDisplaysDataType.

$ system_profiler SPDisplaysDataType
Graphics/Displays:

    NVIDIA GeForce 9400M:

      Chipset Model: NVIDIA GeForce 9400M
      Type: GPU
      Bus: PCI
      VRAM (Total): 256 MB
      Vendor: NVIDIA (0x10de)
      Device ID: 0x0863
      Revision ID: 0x00b1
      ROM Revision: 3448
      gMux Version: 1.8.8
      Displays:
        Color LCD:
          Display Type: LCD
          Resolution: 1440 x 900
          Pixel Depth: 32-Bit Color (ARGB8888)
          Main Display: Yes
          Mirror: Off
          Online: Yes
          Built-In: Yes

    NVIDIA GeForce 9600M GT:

      Chipset Model: NVIDIA GeForce 9600M GT
      Type: GPU
      Bus: PCIe
      PCIe Lane Width: x16
      VRAM (Total): 512 MB
      Vendor: NVIDIA (0x10de)
      Device ID: 0x0647
      Revision ID: 0x00a1
      ROM Revision: 3448
      gMux Version: 1.8.8

In the example above, the video resolution for the MacBook Pro on which I ran the command is 1440 x 900. The Screen Information page at BrowserSpy.dk will also report a system's screen resolution, if you visit that page using a browser on the system. In this case it reports a width of 1440 and a height of 900 pixels for the MacBook Pro.

[/os/os-x] permanent link

Mon, Mar 10, 2014 10:29 pm

Debug output for calendar plugin for Blosxom

I've been using Blosxom for this blog and version 0+6i of the calendar plugin for Blosxom written by Todd Larason whose website seems to no longer be extant, though it is available through the Internet Archive's WayBack Machine here. The last time the Internet Archive archived the site was on March 25, 2010. The plugin can be downloaded from this site at Calendar Plugin for Blosxom.

The plugin has been contributing a lot of entries in the site's error log that appear to be related to normal behavior for the plugin. I've been ignoring them, since the plugin has been working fine and the entries seem to be more informatonal in nature than reflective of a problem with the plugin. E.g., I see a lot of entries similar to the following:

[Sun Mar 09 23:59:19 2014] [error] [client 10.0.90.23] calendar debug 1: start() called, enabled [Sun Mar 09 23:59:20 2014] [error] [client 10.0.90.23] calendar debug 1: filter() called [Sun Mar 09 23:59:20 2014] [error] [client 10.0.90.23] calendar debug 1: Using cached state [Sun Mar 09 23:59:20 2014] [error] [client 10.0.90.23] calendar debug 1: head() called [Sun Mar 09 23:59:20 2014] [error] [client 10.0.90.23] calendar debug 1: head() done, length($month_calendar, $year_calendar, $calendar) = 3947 1212 5229

I finally decided I should stop the production of those entries, though, so I could more readily see log entries that are significant. So I looked at the Perl code for the plugin. On line 30, I see the following:

$debug_level    = 1 unless defined $debug_level;

The debug surboutine is on lines 49 through 56 and is as follows:

sub debug {
    my ($level, @msg) = @_;

    if ($debug_level >= $level) {
        print STDERR "$package debug $level: @msg\n";
    }
    1;
}

On line 517, I see the following comment.

C<$debug_level> can be set to a value between 0 and 5; 0 will output
no debug information, while 5 will be very verbose.  The default is 1,
and should be changed after you've verified the plugin is working
correctly.

Since the plugin has been working for a long time and I don't need to see the debugging information, I set the value for debug_level on line 30 to zero instead of one.

$debug_level    = 0 unless defined $debug_level;

That has stopped the insertion of the calendar plugin entries in the Apache error log file with no effect on the calendar's functionality.

[/network/web/blogging/blosxom] permanent link

Sun, Mar 09, 2014 4:04 pm

Redirecting a URL on an Apache Web Server

If you are using an Apache webserver and you need to redirect visitors to a webpage to another webpage, instead, one method of doing so is to use a server-side redirect, which can be accomplished by inserting a redirect in an .htaccess file, to the new page.

[ More Info ]

[/network/web/server/apache] permanent link

Sat, Mar 08, 2014 10:14 pm

Turning off command echo in MUSHclient but retaining command history

For MUSHclient, if you don't want commands echoed back to you when you type them, but want them stored in the command history, leave command echo turned on. You can check that it is turned on after you connect to the MUSH by clicking on Display. You should not see a check mark next to No Command Echo. If one is there click on No Command Echo to uncheck it.

MUSHClient command echo

You then need to take the following steps:

Click on Game.
Select Configuration.
Select All Configuration.
Uncheck the checkbox next to "Echo My Input In" under Output Window.
Make sure the value for the number of lines to keep under Command History is not set to 0, but is set to the number of commands you want to keep in the history; the default value is 1,000 lines..
Click on OK.

You should then be able to see commands you type in the command history window that you can open with Ctrl-H. If you want to save the setting so that you don't have to change it the next time you connect to the MUSH, click on File and select Save World Details.

Instructions appy to version 4.84.

[/gaming/mushclient] permanent link

Fri, Mar 07, 2014 10:20 pm

Using mdfind to locate files

On a Mac OS X system, you can use the mdfind command to locate files on the system from a command line interface, e.g., from a shell prompt that you may obtain by running the Terminal program, which is located in Applications/Utilities. You can specify the name of the file using the -name option.

$ mdfind -name Waterfalls.mp3
/Users/jdoe/Music/iTunes/iTunes Media/Music/Bob Weir/Relax With Soothing Waterfalls/01 Soothing Waterfalls.mp3
/Users/jdoe/Downloads/Waterfalls.mp3

You can specify just part of the file name and the search is not case specific, i.e., "waterfall" and "Waterfall" are deemed identical.

$ mdfind -name waterfall
/Users/jdoe/Downloads/Waterfalls.mp3
/Users/jdoe/Music/iTunes/iTunes Media/Music/Bob Weir/Relax With Soothing Waterfalls/01 Soothing Waterfalls.mp3
/Users/jdoe/Music/iTunes/iTunes Media/Music/Bob Weir/Relax With Soothing Waterfalls
/Library/Desktop Pictures/Eagle & Waterfall.jpg

As shown in the above example, directories whose names contain the string on which you are performing the search, i.e., "waterfall" in the above case, will also be returned.

If you just want a count of files and directories containing a particular string, such as "waterfall" in the name, you can add the -count parameter.

$ mdfind -count -name waterfall
4

If you want to limit the search to a particular directory you can use the -onlyin parameter.

$ mdfind -name waterfall -onlyin "/Library/Desktop Pictures/"
/Library/Desktop Pictures/Eagle & Waterfall.jpg

[/os/os-x] permanent link

Thu, Mar 06, 2014 10:43 pm

Using sw_vers to obtain OS X version

On a MAC OS X system, you can obtain information on the operating system version from a command line interface, e.g. from a terminal session, which you can get by running the Terminal program in Applications/Utilities, by using the sw_vers command.

$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.8.3
BuildVersion:	12D78

If you are only interested in the ProductName, ProductVersion , or BuildVersion, you can specify arguments that will restrict the output to just that informaton.

$ sw_vers -productName
Mac OS X
$ sw_vers -productVersion
10.8.3
$ sw_vers -buildVersion
12D78

You can also get the OS X version number using the system_profiler command.

$ system_profiler SPSoftwareDataType | grep "System Version"
      System Version: OS X 10.8.3 (12D78)

[/os/os-x] permanent link

Wed, Mar 05, 2014 10:38 pm

Audio File Play - afplay

On Mac OS X systems you can play an audio file, such as an MP3 file, from a command-line interface, i.e., a shell prompt, which you can get by running the Terminal program found in /Applications/Utilities, by using the audio file play command, afplay. E.g.:

afplay Waterfalls.mp3

You can terminate the playing of the audio file using Ctrl-C. You can specify that the audio file only be played for a specific number of seconds using the -t or --time argument. E.g., the following command would play the specified MP3 file for 10 seconds and then terminate afplay:

afplay --time 10 Waterfalls.mp3

For help on the command use afplay -h.

$ afplay -h
Usage:
afplay [option...] audio_file

Options: (may appear before or after arguments)
  {-v | --volume} VOLUME
    set the volume for playback of the file
  {-h | --help}
    print help
  { --leaks}
    run leaks analysis
  {-t | --time} TIME
    play for TIME seconds
  {-r | --rate} RATE
    play at playback rate
  {-q | --rQuality} QUALITY
    set the quality used for rate-scaled playback (default is 0 - low quality, 1 - high quality)
  {-d | --debug}
    debug print output

[/os/os-x] permanent link

Tue, Mar 04, 2014 11:35 pm

Obtaining info on an audio file with afinfo

You can obtain information on an audio file, such as an MP3 file on a Mac OS X system from the command line using the afinfo command.

$ afinfo Waterfalls.mp3
File:           Waterfalls.mp3
File type ID:   MPG3
Num Tracks:     1
----
Data format:     2 ch,  44100 Hz, '.mp3' (0x00000000) 0 bits/channel, 0 bytes/packet, 1152 frames/packet, 0 bytes/frame
                no channel layout.
estimated duration: 3642.644850 sec
audio bytes: 72852897
audio packets: 139445
bit rate: 160000 bits per second
packet size upper bound: 1052
maximum packet size: 523
audio data file offset: 2228
optimized
audio 160637484 valid frames + 528 priming + 2628 remainder = 160640640
----

The command will tell you the bit rate and the estimated duration if you choose to play the file. In the example above, the MP3 bitrate is 160 kbit/s, which is a mid-range bitrate quality for an MP3 file. Common bitrates for MP3 files are as follows:

32 kbit/s – generally acceptable only for speech
96 kbit/s – generally used for speech or low-quality streaming
128 or 160 kbit/s – mid-range bitrate quality
192 kbit/s – a commonly used high-quality bitrate
320 kbit/s – highest level supported by MP3 standard

The estimated playing time of the MP3 file in the example above is 3642.644850 sec. You can convert that to minutes from the command line by passing a command to python to convert seconds to minutes.

$ python -c "print 3642.644850 / 60"
60.7107475

If you wanted to convert that to hours, you could just divide by 60 minutes per hour by adding another "/ 60" at the end of the command.

$ python -c "print 3642.644850 / 60 / 60"
1.01184579167

If you just want to know the bit rate, you can pipe the output of afinfo through grep and awk:

$ afinfo Waterfalls.mp3 | grep "bit rate" | awk '{print $3}'
160000

If you just want to know the duration in seconds, you can use the following commands:

$ afinfo Waterfalls.mp3 | grep "estimated duration" | awk '{print $3}'
3642.644850

If you want the value in minutes you can also use awk to print that value instead.

$ afinfo Waterfalls.mp3 | grep "estimated duration" | awk '{print $3 / 60 , "minutes"}' 
60.7107 minutes

[/os/os-x] permanent link

Mon, Mar 03, 2014 7:31 pm

YandexBot Web Crawler

When checking my website logs to see if there were any entries indicating it had been "crawled", i.e., indexed, by DuckDuckGo, I found that there were no log entries for any of the IP addresses used by the DuckDuckGoBot for indexing webpages for 2013 nor for 2014. I found at DuckDuckGo's Sources webpage that though the search engine has its own web crawler, it relies heavily on indexes produced by the web crawlers for other search engines stating:

DuckDuckGo gets its results from over one hundred sources, including DuckDuckBot (our own crawler), crowd-sourced sites (like Wikipedia, which are stored in our own index), Yahoo! (through BOSS), Yandex, WolframAlpha, and Bing.

DuckDuckGo's page states they apply their own algorithm to rank results obtained from other search engines upon which they rely for data.

One of the search engines mentioned was Yandex. The Yandex search engine, Yandex Search, can be accessed at www.yandex.com. According to the Wikipedia articles for Yandex and Yandex Search the company operates the largest search engine in Russia with about 60% market share in Russia with its search engine generating 64% of all Russian web search traffic in 2010. The article on the company also states:

Yandex ranked as the 4th largest search engine worldwide, based on information from Comscore.com, with more than 150 million searches per day as of April 2012, and more than 50.5 million visitors (all company's services) daily as of February 2013.

The article also indicates Yandex is heavily utilized in Ukraine and Kazakhstan, providing nearly a 1/3 of all search results in those countries and 43% of all search results in Belarus.

When I searched the logs for this year for this website, I found quite a few entries indicating the site had been indexed by the Yandex web crawler. I.e., there were many entries containing the following:

"Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)"

In the homepage for this site, I include PHP code to notify me whenever Google's Googlebot indexes the site, so I updated that code to include a check that will lead to an email alert being sent to me whenever the YandexBot indicates the site, also.


<?php
$email = "me@example.com";
if( eregi("googlebot", $_SERVER['HTTP_USER_AGENT']) )
{
    mail($email, "Googlebot Alert",
            "Google just indexed your following page: " .
            $_SERVER['REQUEST_URI']);
}

if( eregi("YandexBot", $_SERVER['HTTP_USER_AGENT']) )
{
    mail($email, "Yandex Alert",
            "Yandex just indexed your following page: " .
            $_SERVER['REQUEST_URI']);
}

?>

[/network/web/search] permanent link

Mon, Mar 03, 2014 5:17 pm

Removing a site from search results

If you don't wish to have any results returned for a particular site when you are performing a search using Google, Bing, Yahoo, or DuckDuckGo, you can include the option -site on the search line. E.g., if I wished to search for "accessing deleted wikipedia pages", but didn't want any results returned from Wikipedia.org, I could use the following search terms:

accessing deleted wikipedia pages -site:wikipedia.org

If you wish to include only results for a particular site, then you would put the site's name after the word site, e.g., if I wished to search just moonpoint.com, I could use the following:

accessing deleted wikipedia pages site:moonpoint.com

If you restrict searches using the site option, if you use a domain name such as moonpoint.com, results will also be returned for any domain names that include the specified domain name at the end of the domain name, e.g., in this case anything on www.moonpoint.com or support.moonpoint.com would also be returned. The same is true when using the -site option, i.e., no results would be returned for en.wikipedia.org or www.wikipedia.org in the first example.

[/network/web/search] permanent link

Sun, Mar 02, 2014 10:40 pm

F-Secure Rescue CD 3.16

F-Secure provides a free Rescue CD which allows you to boot a PC from a CD and scan it for malware using F-Secure's antivirus software. The F-Secure Rescue CD will attempt to disinfect any infected files and will rename any it can't disinfect by putting a .virus extension at the end of the file name. By doing that, when you reboot the system into Microsoft Windows, the infected file will not be loaded into memory.

[ More Info ]

[/security/antivirus/f-secure] permanent link

Sun, Mar 02, 2014 10:36 pm

Installing the SSH Server Service on Knoppix

You can determine if a Knoppix Linux system is listening for SSH connections on the standard SSH TCP port of 22 by issuing the command netstat -a | grep ssh. If you are returned to the shell prompt with no results displayed, then the system isn't listening for SSH connections on port 22.

root@Microknoppix:/# netstat -a | grep ssh
root@Microknoppix:/#

You can also check to see if it is running by using the command service --status-all. If there is a plus sign next to ssh, it is running. If, instead, there is a minus sign, it is not running.

root@Microknoppix:/# service --status-all
 [ - ]  acpid
 [ - ]  bootlogd
 [ - ]  bootlogs
 [ ? ]  bootmisc.sh
 [ ? ]  checkfs.sh
 [ - ]  checkroot.sh
 [ ? ]  console-screen.sh
 [ ? ]  console-setup
 [ ? ]  cpufrequtils
 [ ? ]  cron
 [ ? ]  cryptdisks
 [ ? ]  cryptdisks-early
 [ + ]  dbus
 [ + ]  ebtables
 [ ? ]  etc-setserial
 [ - ]  fsaua
 [ ? ]  fsrcdtest
 [ - ]  fsupdate
 [ ? ]  fsusbstorage
 [ ? ]  gpm
 [ ? ]  hdparm
 [ - ]  hostname.sh
 [ ? ]  hwclock.sh
 [ ? ]  hwclockfirst.sh
 [ ? ]  ifupdown
 [ ? ]  ifupdown-clean
 [ ? ]  kexec
 [ ? ]  kexec-load
 [ ? ]  keyboard-setup
 [ ? ]  keymap.sh
 [ ? ]  killprocs
 [ ? ]  klogd
 [ ? ]  knoppix-autoconfig
 [ ? ]  knoppix-halt
 [ ? ]  knoppix-reboot
 [ ? ]  knoppix-startx
 [ ? ]  loadcpufreq
 [ ? ]  lvm2
 [ ? ]  mdadm
 [ ? ]  mdadm-raid
 [ ? ]  module-init-tools
 [ ? ]  mountall-bootclean.sh
 [ ? ]  mountall.sh
 [ ? ]  mountdevsubfs.sh
 [ ? ]  mountkernfs.sh
 [ ? ]  mountnfs-bootclean.sh
 [ ? ]  mountnfs.sh
 [ ? ]  mountoverflowtmp
 [ ? ]  mtab.sh
 [ + ]  network-manager
 [ ? ]  networking
 [ - ]  nfs-common
 [ - ]  nfs-kernel-server
 [ + ]  open-iscsi
 [ - ]  portmap
 [ ? ]  pppstatus
 [ ? ]  procps
 [ ? ]  rc.local
 [ - ]  rmnologin
 [ - ]  rsync
 [ ? ]  screen-cleanup
 [ ? ]  sendsigs
 [ ? ]  setserial
 [ - ]  smartmontools
 [ - ]  ssh
 [ - ]  stop-bootlogd
 [ - ]  stop-bootlogd-single
 [ ? ]  sudo
 [ ? ]  sysklogd
 [ ? ]  udev
 [ ? ]  udev-mtab
 [ ? ]  umountfs
 [ ? ]  umountiscsi.sh
 [ ? ]  umountnfs.sh
 [ ? ]  umountroot
 [ - ]  urandom

On a Microknoppix system, such as may be present on a Rescue CD or other live CD or DVD, the SSH server software may not even be present on the CD or DVD. You can use the apt-cache search command followed by a regular expression, in this case ssh, to determine if the package is present on the system.

root@Microknoppix:/# apt-cache search ssh
libssl0.9.8 - SSL shared libraries
sshstart-knoppix - Starts SSH and sets a password for the knoppix user
openssh-client - secure shell (SSH) client, for secure access to remote machines

In the case above, I can see that only an SSH client is present. If I run the sshstart-knoppix command, I will be prompted to set a password for the knoppix account on the system, but, since the SSH server package is not present, the command won't actually start an sshd service.

If the SSH server service is not running and the SSH server package is not installed, first you need to install the SSH server software. To do so you may need to add an appropriate package repository, such as http://us.debian.org/debian to the file /etc/apt/sources.list. E.g., you will need to do so when using the F-Secure 3.16 Rescue CD.

If you attempt to install the openssh-server package and see the results below, then you need to add an appropriate repository to /etc/apt/sources.list so the system can find the package and download it.

root@Microknoppix:/# apt-get install openssh-server
Reading package lists... Done
Building dependency tree...
Reading state information... Done
Package openssh-server is not available, but is referred to by another package.
This may mean that the package is missiong, has been obsoleted, or
is only available from another source

E: Package 'openssh-server' has no installation candiate
root@Microknoppix:/#

You can add the http://us.debian.org/debian repository to the end of the file by using the cat command. Type cat >> /etc/apt/sources.list (make sure you use two greater than signs so as to append to the file rather than overwrite it) then type deb http://http.us.debian.org/debian stable main contrib non-free and then hit Enter. Then hit the Ctrl and D keys simultaneously, i.e., Ctrl-D. Next issue the command apt-get update. When that command has completed, issue the command apt-get install openssh-server. When informed of the amount of additional disk space that will be needed and them prompted as to whether you wish to continue, type "Y". When prompted "Install these packages without verification [y/N]?", enter "y".

When the command completes you can then issue the command netstat -a | grep ssh to verify that the system is listening on the SSH port, which is normally TCP port 22.

root@Microknoppix:/# netstat -a | grep ssh
tcp        0      0 *:ssh                   *:*                     LISTEN     
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN

If you issued the command apt-cache search openssh-server at this point, you would see the following:

root@Microknoppix:/# apt-cache search openssh-server
openssh-server - secure shell (SSH) server, for secure access from remote machines

Use the passwd command to set the password for the knoppix account, which you can use for remote logins.

root@Microknoppix:/tmp# passwd knoppix
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

Hit Return to continue.

Once the SSH server service is running, you should be able to connect to the system remotely with an SSH client on another system. To determine what IP address you should use for the connection, you can issue the command ifconfig. You should see an inet addr line that will provide the system's current IP address. It will typically be in the information provided for the eth0 network interface. The l0 interface is the local loopback interface, which will have an IP address of 127.0.0.1. You can use that address to verify that the SSH connectivity is working from the local system, but not for a remote login.

root@Microknoppix:/# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:18:f3:a6:01:8a  
          inet addr:192.168.0.40  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::218:f3ff:fea6:18a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:334286 errors:0 dropped:0 overruns:0 frame:0
          TX packets:262393 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:289663552 (276.2 MiB)  TX bytes:183570787 (175.0 MiB)
          Interrupt:23 Base address:0xc000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:2331 (2.2 KiB)  TX bytes:2331 (2.2 KiB)

To login remotely via SSH, use knoppix for the login account and provide the password you entered above for that account when prompted for the password. Once you have logged in under the knoppix account, you can obtain a Bash shell prompt for the root account using the command sudo bash.

knoppix@Microknoppix:~$ sudo bash
root@Microknoppix:/home/knoppix#

If you then need to stop, start, or restart the service, you can do so using /etc/init.d/ssh followed by the appropriate parameter.

root@Microknoppix:/# /etc/init.d/ssh
[info] Usage: /etc/init.d/ssh {start|stop|reload|force-reload|restart|try-restar
t|status}.

The configuration file for the SSHD service is /etc/ssh/ssh_config. You can change values by removing the comment character, #, from the beginning of a line and chaning the default value on the line, then stopping and restaring the service. Note: stopping the sshd service won't disconnect an existing SSH connection, so you can remotely restart the service with /etc/init.d/ssh restart without being disconnected.

[/os/unix/linux/knoppix] permanent link

Sat, Mar 01, 2014 11:28 am

Using multiple conditions with find

The find command on Unix/Linux and Apple OS X systems allows you to specify multiple criteria to be used for a search. For instance, suppose I have a directory named man and a file named manual.txt. If I wanted to find any files or directories containing "man" within their names, I could issue the command below. If the directory in which the find command was executed contained a subdirectory named man and a text file named manual.txt, I would see the results shown below:

$ find . -name \*man\*
./man
./manual.txt

Note: the backslashes before the asterisks are "escape characters", i.e., they tell the shell not to interpret the asterisk before the find command sees it - see What is the difference between \*.xml and *.xml in find command in Linux/mac. Another alternative is to enclose the *man* within double quotes.

$ find . -name "*man*"
./man
./manual.txt

But, if I only want to find items that have "man" in the name which are directories, I could use the following to specify I only want to see items where the file is of type directory ("d" represents directory and "f" represents a regular file):

$ find . -name \*man\* -type d
./man

By default, the find command will use a logical and for the two conditions, i.e., both conditions must be met. I could explicitly state I want to "and" the two conditions with a -a, but it isn't necessary to do so in this case.

$ find . -name \*man\* -a -type d
./man

But what if I want to to specify a logical "or", i.e. that I want results returned where either of two conditions are met? E.g., suppose I want to find all files where the filename contains man or guide. Then I need to use a -o parameter.

$ find . -name "*man*" -o -name "*guide*"
./man
./manual.txt
./guide.txt

Suppose I only wanted to see only files with man or guide in the filename that are "regular" files and not any directories. I could use -type f to specify that I only want to see regular files.

$ find . -name "*man*" -o -name "*guide*" -type f
./man
./manual.txt
./guide.txt

As you can see, the directory man is still returned. To get the results I want, i.e., to not have the directory man appear in the results, I need to enclose the "or" condtions within parentheses.

$ find . \( -name "*man*" -o -name "*guide*" \) -type f
./manual.txt
./guide.txt

Note: you also need to "escape" the meaning of ( and ) by preceding them with the backslash escape character. Otherwise, you will get an "unexpected token" error message.

$ find . (-name "*man*" -o -name "*guide*") -type f
-bash: syntax error near unexpected token `('

And you need to put a space after the left parenthesis and before the right parenthesis or you will receive an "invalid predicate" error message.

$ find . \(-name "*man*" -o -name "*guide*"\) -type f
find: invalid predicate `(-name'

As another example, suppose I want to find all HTML or PHP files that contain the word "Geek" within them when the HTML files have a .html extension and the PHP files have a .php extension on the file names. Then I need to use a -o between the conditions to specify that I want to see results if the file has an extension of .html or .php.

$ find . \( -name "*.php" -o -name "*.html" \) -exec grep -i "Geeks" {} /dev/null \;
./temp.php:1Geeks
./temp.html:2Geeks

Whenever a file has a name that ends in .html or .php, the file contents are sent to the grep command for examination. To specify that I want to use a logical or, the -o is placed between -name "*.php" and -name "*.html". Again, I also have to include the two conditions within parentheses to ensure that the "or" condition is checked before sending the results to grep for examination of the contents of the files. If the parentheses aren't used, I would only see one of the files returned.

$ find . -name "*.php" -o -name "*.html" -exec grep -i "Geeks" {} /dev/null \;
./temp.html:2Geeks

[/os/unix/commands] permanent link

Mon, Mar 31, 2014 11:03 pm

Sun, Mar 30, 2014 10:38 pm

Sat, Mar 29, 2014 4:24 pm

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Fri, Mar 28, 2014 10:12 pm

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Wed, Mar 26, 2014 9:21 pm

Tue, Mar 25, 2014 9:13 pm

Mon, Mar 24, 2014 8:17 am

Sun, Mar 23, 2014 2:08 pm

Sun, Mar 23, 2014 1:31 pm

Sat, Mar 22, 2014 10:49 pm

Sat, Mar 22, 2014 5:42 pm

Sat, Mar 22, 2014 2:10 pm

Fri, Mar 21, 2014 9:55 pm

Thu, Mar 20, 2014 9:21 pm

Wed, Mar 19, 2014 11:17 pm

Tue, Mar 18, 2014 10:34 pm

Mon, Mar 17, 2014 5:48 pm

Mon, Mar 17, 2014 5:30 pm

Sun, Mar 16, 2014 11:59 am

Sun, Mar 16, 2014 9:41 am

Sat, Mar 15, 2014 11:17 am

Fri, Mar 14, 2014 10:30 pm

Fri, Mar 14, 2014 9:55 am

Thu, Mar 13, 2014 11:15 pm

Wed, Mar 12, 2014 11:40 pm

Tue, Mar 11, 2014 10:31 pm

Mon, Mar 10, 2014 10:29 pm

Sun, Mar 09, 2014 4:04 pm

Sat, Mar 08, 2014 10:14 pm

Fri, Mar 07, 2014 10:20 pm

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Tue, Mar 04, 2014 11:35 pm

Mon, Mar 03, 2014 7:31 pm

Mon, Mar 03, 2014 5:17 pm

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Sun, Mar 02, 2014 10:36 pm

Sat, Mar 01, 2014 11:28 am