Category Archives: Tips
Control M ( ^M) characters are introduced when you use lines of text from a windows computer to Linux or Unix machine. Most common reasons are when you directly copy a file from a windows system or submit form data copied and pasted from a windows machine.
Detecting ^M characters
^M is non printable character and often becomes difficult to find, in order to see if your file contains any non printable character use the cat command with -v option
$cat -v filename
Methods to remove ^M
In all these method , real secret is not to type ^M using keyboard but rather typing in control key sequence to get the ^M control character.
Published several years ago these O’Reilly books are still useful & relevant for the current and new system administrators. Although these books may not cover latest version of operating systems yet these explains very well the underlying technical details and process which have not changed over the years.
Learn to use awk for text and data extraction, data processing, validation, generate reports for analysis, automation with with the help of examples of if else , compare & arrays plus regular expressions & built in operational variables, meaning, examples &command syntax.
Windows Xp support is stopping on April 8, 2014 and one of the issues is that when you migrate to current Windows operating systems ( windows 8 ) old ie browsers are not supported for installation. Current OS Windows 8 comes with ie 10 and older versions of ie are not supported.
The biggest problem is that many of corporate applications which are designed long back and no longer supported may still need older ie 7 , 8 or 9
Learn about Linux and Unix date & time formating with the help of simple explanation and added example. Date command in Unix & Linux is used to format date as well as time. First portion of this article covers Date function and the second portion has the time function covered.
Date time formatting in PHP
Many scripts written in php need date and time function . PHP has many predfined date formats and you can also customized it as per your need .
Here are some of the date format examples and additional details for php.
How to configure passwordless ssh & sftp access in Unix & Linux systems? Follow these simple steps with examples with a basic troubleshooting section at the end. sftp uses underlying ssh access for authentication and after you establish passwordless ssh access you will have passwordless sftp access a s well.
This a real life example of configuring passwordless access for two users . The user ‘web’ in this case needs a secure password less access to another user james in a server ‘devserver’
- Running Sol
aris in 32 or 64 bit mode – Page 1
- Removing ^M from Unix text files – Page 2
- Backup commands – ufsdump , tar , cpio – Page 3
- Setting up Ethernet card speed & duplex mode – Page 4
- One Line scripts – Page 4
Setting up cron jobs in Unix, Solaris & Linux
cron is a unix, solaris, Linux utility that allows tasks to be automatically run in the background at regular intervals by the cron daemon.
Learn about the Unix commands with their usages and examples.
This Unix command tutorial introduces you with some of the most popular and useful commands used in nix operating system to get you started with Unix.
All Unix OS comes with online manual system, man, which can be used used as ,man
DNS troubleshooting , this article describes some of the common dns problems and their solutions.
First phase of article describes dns errors relating to configuration , server setup and its basic functionality . Second phase talks about the nslookup related errors when the dns servers seems to be working correctly but names resolution fail .
fsck, similar to chkdsk in windows, checks and repairs the file system in Unix & Linux operating systems. Learn about fsck modes, phases & fsck errors messages
fsck, File System Consistency checK, is a system utility in Unix, Linux and other Unix like systems for checking and repairing file system inconsistencies.
File system can become inconsistent due to several reasons and the most common is abnormal shutdown due to hardware failure, power failure or switching off the system without proper shutdown. Due to these reasons the superblock in a file system is not updated and has mismatched information relating to system data blocks, free blocks and inodes.
fsck in Linux
fsck in this document is refered with reference to ufs file system but it can be used in Linux systems as
fsck -t ext2 /dev/sda3
it returns with any of the followig code
0 – No errors
1 – File system errors corrected
2 – System should be rebooted
4 – File system errors left uncorrected
8 – Operational error
16 – Usage or syntax error
32 – Fsck canceled by user request
128 – Shared library error
fsck checks the file systems defined in /etc/fstab in Linux and /etc/vfstab in Unix systems