wget -qO- http://www.mywebsite.com/file.htm

So, my latest issue is I needed to search through lots of logs to find an email address.  Normally I’d use grep to parse through the files.  Instead I opened up a Powershell prompt and used the following command

findstr /I my@email.com logfile.log

Findstr is just like grep and has a lot of the same options.  The /I tells it to be case-insensitive.  The my@email.com is what I’m looking for in logfile.log.  Here are the different settings that you can use:

FINDSTR [/B] [/E] [/L] [/R] [/S] [/I] [/X] [/V] [/N] [/M] [/O] [/P] [/F:file]
[/C:string] [/G:file] [/D:dir list] [/A:color attributes] [/OFF[LINE]]
strings [[drive:][path]filename[ ...]]

/B         Matches pattern if at the beginning of a line.
/E         Matches pattern if at the end of a line.
/L         Uses search strings literally.
/R         Uses search strings as regular expressions.
/S         Searches for matching files in the current directory and all
subdirectories.
/I         Specifies that the search is not to be case-sensitive.
/X         Prints lines that match exactly.
/V         Prints only lines that do not contain a match.
/N         Prints the line number before each line that matches.
/M         Prints only the filename if a file contains a match.
/O         Prints character offset before each matching line.
/P         Skip files with non-printable characters.
/OFF[LINE] Do not skip files with offline attribute set.
/A:attr    Specifies color attribute with two hex digits. See “color /?”
/F:file    Reads file list from the specified file(/ stands for console).
/C:string  Uses specified string as a literal search string.
/G:file    Gets search strings from the specified file(/ stands for console).
/D:dir     Search a semicolon delimited list of directories
strings    Text to be searched for.
[drive:][path]filename
Specifies a file or files to search.

Use spaces to separate multiple search strings unless the argument is prefixed
with /C.  For example, ‘FINDSTR “hello there” x.y’ searches for “hello” or
“there” in file x.y.  ‘FINDSTR /C:”hello there” x.y’ searches for
“hello there” in file x.y.

Regular expression quick reference:
.        Wildcard: any character
*        Repeat: zero or more occurrences of previous character or class
^        Line position: beginning of line
$        Line position: end of line
[class]  Character class: any one character in set
[^class] Inverse class: any one character not in set
[x-y]    Range: any characters within the specified range
\x       Escape: literal use of metacharacter x
\<xyz    Word position: beginning of word
xyz\>    Word position: end of word

For full information on FINDSTR regular expressions refer to the online Command
Reference.

/scripts/pkgacct [username]

My latest “find” with the find command came about because on one of my JBoss servers I wrote a simple script that looks for log files older than 15 days and deletes them and looks for other log files older than 61 minutes and compresses them with gzip.

#!/bin/bash
LOGS=/usr/local/jboss/server/all/log/
#delete all logs older than 37 days
find $LOGS -mtime +15 | xargs rm -rf
# gzip files last modify at least 1 hour ago
find $LOGS -mmin +61 | xargs gzip

Our JBoss setup automatically writes new logs to server.info.log and server.error.log, then every every hour it renames the INFO and ERROR log to the current date + hour, so server.info.log would be changed to server.info.log.2010-03-09-13 for today at 2pm to roll out the 1pm logs.

The problem I came across in my script was with my server.error.log file.  If an error hasn’t been written to the server.error.log file during that hour, it wasn’t going to rotate an empty error log.  Since the file hadn’t been touched/updated/modified in over 61 minutes, my script came along and gzipped it, at this point JBoss then had a problem because the error log was missing and didn’t create a new one.

So what I needed to do was to find all the files that matched the criteria, but exclude the server.info.log and server.error.log and here is my final script.

#!/bin/bash
LOGS=/usr/local/jboss/server/all/log/
INFOLOG=”server.info.log”
ERRORLOG=”server.error.log”
#delete all logs older than 37 days
find $LOGS -mtime +15 -not -name “$INFOLOG” -not -name “$ERRORLOG” | xargs rm -rf
# gzip files last modify at least 1 hour ago
find $LOGS -mmin +61 -not -name “$INFOLOG” -not -name “$ERRORLOG” | xargs gzip

cat FILENAME | tr “[:upper:]” “[:lower:]“

Or to go from lowercase to uppercase:

cat FILENAME | tr “[:lower:]” “[:upper:]“

ifconfig eth0:2 1.1.1.2 netmask 255.255.255.0 up
ifconfig eth0:3 1.1.1.3 netmask 255.255.255.0 up
and so on to…..
ifconfig eth0:200 1.1.1.200 netmask 255.255.255.0 up

Well, I’m always looking for an easier way, so I turned to my friend BASH and a tool called SEQ.  SEQ will give you a sequence of numbers.  For example if you just wanted 10 numbers you could do the following:

[matt@localhost ~]$ seq 5
1
2
3
4
5

So for this task I needed to bring up IP addresses from 2 through 254.  Running “seq 2 254″ will give me a sequence from 2 to 254, I need more than just to have a list of numbers, I actually need to use them, so here’s the syntax I used to use the numbers to bring up each of the interfaces

for i in $(seq 2 254)
do
ifconfig eth0:$i 1.1.1.$i netmask 255.255.255.0 up
done

Obviously in the above example, you would substitute the sequence you want to use and the IP subnet you want to use.  Also, this syntax would put 1.1.1.2 on sub-interface eth0:2, 1.1.1.3 on sub-interface eth0:3, etc.

curl --interface xxx.xxx.xxx.xxx -s http://www.sysadminvalley.com

Make sure that you substitute xxx.xxx.xxx.xxx with the IP address you want to use.

root@localhost# openssl genrsa -out www.mydomain.com.key 1024
Generating RSA private key, 1024 bit long modulus
………….++++++
………………..++++++
e is 65537 (0×10001)

Then, we need to generate the certificate request and fill in the appropriate information.  Make sure that the “Common Name” matches the domain you want to protect via SSL, so if you domain was www.mydomain.com, use that.  If you wanted to protect mydomain.com (without the www.) then use that.

root@localhost# openssl req -new -key www.mydomain.com.key -out www.mydomain.com.csr
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter ‘.’, the field will be left blank.
—–
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server’s hostname) []:www.mydomain.com
Email Address []:email@mydomain.com

Please enter the following ‘extra’ attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Next, generate the self-signed certificate. You can specify the number of days the cert is valid for.

root@localhost# openssl x509 -req -days 365 -in www.mydomain.com.csr -signkey www.mydomain.com.key -out www.mydomain.com.crt
Signature ok
subject=/C=/ST=/L=/O=/CN=www.mydomain.com/emailAddress=email@mydomain.com
Getting Private key

Next, move the certificate and keyfile into apache’s SSL directory.

mv www.mydomain.com.key /etc/httpd/conf/ssl.key/
mv www.mydomain.com.crt /etc/httpd/conf/ssl.crt/

Finally, we configure our SSL virtual host in Apache.  The simplest way to do this is to copy the virtual host for the site you want to make SSL, then add/change the following bits.

<VirtualHost 192.168.1.100:443>
…
SSLEngine on
SSLCertificateFile /etc/httpd/conf/ssl.key/www.mydomain.com.key
SSLCertificateKeyFile /etc/httpd/conf/ssl.crt/www.mydomain.com.crt
…
</VirtualHost>

for file in `ls *.php`
do
sed -e ‘s/Copyright 2008/Copyright 2009/’ “$file” > tmp_file
mv -f tmp_file “$file”
done

What this does is get’s a list of all php files in the current directory, puts them in a loop with a variable called FILE, then does a sed search and replace calling the new file tmp_file and moving the temp file back in place.  If you wanted to do it for all files including in subdirectories, you could substitute:

ls *.php

with:

find ./ -name “*.php”

It’s a simple perl script and to use it is really easy.  First, download the script to your linux server, change it to be executable, then run it

wget http://mysqltuner.com/mysqltuner.pl
chmod 0700 mysqltuner.pl
./mysqltuner.pl

You’ll get a great one page output which gives you some great detail about what’s going on, and what settings can be used in your my.cnf file.  One word of caution, make sure you backup your my.cnf before making changes, and you should also spend some time learning what the values mean.