What is IFS in linux bash shell ?
1. Introduction IFS stands for Internal Field Separator in Linux. $IFS is one of the system variable with default value “space, tab, and a new line”. This system variable signifies...
Month: May 2019
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How to color a text/string in linux bash shell & make it blink ?
An interesting thing to do when creating shell scripts is to know how to color some text/output and blink it. Today in this article , we will look how to...
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What are different types of positional parameters available in linux ?
Positional parameters as its name suggests are different positional variables automatically defined by linux shell. The shell automatically assigns the passed parameters according to their position in 9 different parameters(1...
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How to mount a filesystem from backup superblock location ?
Let us look how to mount a filesystem from backup superblock location. In general this is not required, however sometimes in case you feel issue with primary superblock, this way...
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How to search and replace text where line contains some specific string in Linux shell ?
Today we will look how to search some text in a file and replace specific string on the searched line. For this, we will use sed command i.e. Linux Stream...
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Regex to look for multiple characters or words in linux bash shell ?
Today we will look at the regex to search/grep multiple characters or words from a file or output in linux. First create a file with below contents. [root@nglinux ]# cat...
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Use of dot “.” in regular expressions during search/grep in bash shell linux ?
Today we will look at the usage of dot “.” on Linux bash shell and how to use it in shell scripts to match a pattern. I. Usage of “.”...
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How to get length of a string/integer variable in linux bash shell ?
Today in this post, we will look how to get length of a variable in linux whether its a string or integer. Getting variable length in Linux 1. Using shell...
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How to unset variables in linux bash shell (normal and read only variables) ?
We all know that a variable is defined by simply assigning a value to it. However bash shell also provides a feature to unset it, in order to free it...
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How to look/grep for special characters in a file in linux bash shell ?
Today in this post, we will look how to search or grep special characters in a file text. To search special characters in linux, we need to escape them using...