# Sayregexp separator defaults to space
**URL:** https://community.mp3tag.de/t/sayregexp-separator-defaults-to-space/70660
**Category:** Web Sources Discussion
**Created:** [February 9, 2026, 7:23pm UTC](https://community.mp3tag.de/t/sayregexp-separator-defaults-to-space/70660 "2026-02-09T19:23:40Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@yorickausyps](https://community.mp3tag.de/u/yorickausyps)
#### Post date: [February 9, 2026, 7:23pm UTC](https://community.mp3tag.de/t/sayregexp-separator-defaults-to-space/70660/1 "2026-02-09T19:23:40Z")
After wondering for one or two month what's happening in a regular exression I used with a sayregexp command, I was assuming that regular expressions can never be fully understood by normal programmers. But now I found out that sayregexp has an undocumented feature: it's second parameter, the separator, uses a space character as default if it is omitted or set to an empty string of zero length. This means, that the three versions
```auto
sayregexp "a|b|c"
sayregexp "a|b|c" ""
sayregexp "a|b|c" " "
```
are all the same and will separate the matches with a space. Therefore it is not possible to directly concatenate the matches from a sayregexp without a separater between them.
The same observation had been made by @vkostas already [in sept 2012](https://community.mp3tag.de/t/web-source-sayregexp-blank-separator/13945/2) .
I don't want to suggest, that sayregexp should be changed, because that would break several existing scripts, including my own one. Instead it would be great, if @Florian could simply change the documentation and add a hint to the space character being used as default separator.
---
### Author:  [@Florian](https://community.mp3tag.de/u/Florian)
#### Post date: [February 9, 2026, 7:34pm UTC](https://community.mp3tag.de/t/sayregexp-separator-defaults-to-space/70660/2 "2026-02-09T19:34:28Z")
Thanks for pointing, and sorry for omitting this crucial piece of information!
> [@yorickausyps](#):
>
> change the documentation and add a hint to the space character being used as default separator.
Done.
---
### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [April 20, 2026, 9:39am UTC](https://community.mp3tag.de/t/sayregexp-separator-defaults-to-space/70660/3 "2026-04-20T09:39:20Z")
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