Text slicing and parameter operations
This recipe walks through some of the simple text-replacement techniques and parameter-expansion shorthands available in Bash. A few simple techniques can often help us avoid having to write multiple lines of code.
How to do it...
Let's get into the tasks.
Replacing some text from a variable can be done as follows:
$ var="This is a line of text" $ echo ${var/line/REPLACED} This is a REPLACED of text"
line
is replaced with REPLACED
.
We can produce a substring by specifying the start position and string length, by using the following syntax:
${variable_name:start_position:length}
To print from the fifth character onwards, use the following command:
$ string=abcdefghijklmnopqrstuvwxyz $ echo ${string:4} efghijklmnopqrstuvwxyz ...
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