How to know the number of blank spaces consumed by a tabulation ?

Question

Hello everyone,

Im writing a program which reads a file and enable to locate(Line, Column) some word in the file. My problem is when it reaches a tabulation(\t) the Column value is incremented by 1 as it was a simple blank space.

I have also noticed that the blank spaces depend on text editor. So, how can i get the number of blank spaces consumed by a tabulation ?

Answer 1

This has to do on how your text editor processes the so-called "control characters".

On Notepad++, you can configure the number of spaces of a tab as follows:

Settings // Preferences // Language // Tab Settings box // [Default] // Tab size

Answer 2

Mario Álvarez Revuelta Thx for your answer. I know this way. Do u know how can i get it programatically, for example, by using some code ?

Answer 3

I use python.

Let's say you have read a line from a *.txt, stored in S:

>>S = 'asd asd asd asd'

being the first and last blank spaces a tab. If you ask python to print it, it will output the before mentioned S, although internally its interpreted as:

'asd\tasd asd\tasd\n'

Well, you can make this S string to become a raw string through:

>>rawS = '%r'%S

This avoids all control characters to be interpreted, writing them as a string. Let's print it:

>>print(rawS)
'asd\tasd asd\tasd\n'

At this point it would be easy to read all characters and if '\' is found and followed by 't', replace them by the desired number of spaces.

I guess there are simpler ways to solve this, but this is what I would do if I were you and had to work this out quickly. I think that you can use raw string conversion using other programming languages, if you're not on python.

Hope it helps.