Posts Tagged ‘substring’

If you have a filename or list of filenames, you may want to strip the extension. There are a few ways of “detecting” which part of the filename is the extension, but may not work if your file has multiple extensions (e.g. .tar.gz), contains spaces or periods, or meets other weird criteria. If you know […]

There are a few ways to find out if a string contains a substring using bash. Below are a couple of ways this can be done without invoking any other processes. Star Wildcard One very simple method is to match strings using the * character to denote any number of other characters. For example: if […]

Reversing a string in Python

Posted: 25th April 2013 by Tim in Python
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If you need to reverse a string in python, the easiest way is to do use the my_string[::-1] syntax. For example, to print a reversed string, you could write: my_string = “ABCDE” print my_string[::-1] So what is this doing? The square bracket syntax is used for returning a substring. This works like so: [<start>:<end>:<step>]. If […]

If you want to get the last n characters of a string in bash, you can simply mix bash substrings – ${string:offset[:length]} – with bash string lengths – ${#string}. For example: str=”abcde” n=3 echo ${str:${#str} – $n} will print: cde

Substrings in Bash

Posted: 17th October 2010 by Tim in Bash
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There are a number of ways to extract parts of a string in bash. If you know the position of the substring you’re looking for, then you can use the ${string:offset[:length]} syntax. This works by providing a string, an offset (or starting position – remember that the first letter is in position 0) and, optionally, […]