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Bash slice string in Linux Shell

Strings are quite basic in any scripting or programming languages.

If a journey to a thousand miles starts with a single step, in the programming world the journey starts with a string called “Hello World” and beyond “Hello World” pseudocode and algorithm will keep the journey going.  

Strings in scripting or programming are just group of characters.

So, if string is a group of characters then it can be slice by character or a sub-string can be taken from the string.

To slice a string in Bash, a syntax which is part of the Bash library can be used.

Syntax is: ${string_to_be_sliced:slice_start_position:slice_end_position}

Example string: slicethestring=“Hello Algorithm World”

The string is stored in a variable: slicethestring

To get the sub-string “Algorithm World”.

Code will be:  echo ${slicethestring:6:23} #start the slice at position 6 till position 23

Another way to slice the string from a specified start position till the end; is to tell Bash the start position and just omit the end position.

Or in layman terms tell Bash to start at a specified position but don’t tell Bash when to end, in this way Bash will automatically get all the characters until the last position of the string.

Here’s the code: echo ${slicethestring:6}  #this will concatenate until the end of the string but don’t put the “:” after the first position  or else there will be an error because Bash will expect an input following the colon “:”.

Both codes will display: Algorithm World

Here’s the screen shot of the script and the output:

Script:


Sample output:


Cheers..till next time!

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