regex return everything up to the first space after nth character

Question

I have a list of product names and I want to shorten them (Short Name). I need a regex that will return the first word if it is more than 5 characters and the first two words if it is 5 characters or less.

Product Name            Short Name
BABY WIPES MIS /ALOE    BABY WIPES
PKU GEL PAK             PKU GEL
CA ASCORBATE TAB 500MG  CA ASCORBATE
SOD SUL/SULF CRE 10-2%  SOD SUL/SULF
ASPIRIN TAB 81MG EC     ASPIRIN
IRON TAB 325MG          IRON TAB
PEDA                    PEDA

I initially used:

^([^ \t]+).*

but it only returns the first word so BABY WIPES MIS /ALOE would be BABY. I then tried:

.....([^ \t]+)

But this appears to not work for names less than 5 characters. Any help would be greatly appreciated.

Answer 1

Brief

Your try is close, however, since you negated spaces and tabs, you were unable to move past the first word.

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Code

See code in use here

^(\S{1,5}[ \t]*?\S+).*$

Note: The link uses the following shortened regex. \\h may not work in your flavour of regex, which is why the code above is posted as well.

^(\S{1,5}\h*?\S+).*$

Super-simplified it becomes ^\\S{1,5}\\h*?\\S+ (without capture groups and .*$ as the OP initially used.)

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Results

Input

BABY WIPES MIS /ALOE
PKU GEL PAK
CA ASCORBATE TAB 500MG
SOD SUL/SULF CRE 10-2%
ASPIRIN TAB 81MG EC
IRON TAB
PEDA

Output

BABY WIPES
PKU GEL
CA ASCORBATE
SOD SUL/SULF
ASPIRIN
IRON TAB
PEDA

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Explanation

• ^ Assert position at the start of a line
• (\\S{1,5}[ \\t]*?\\S+) Capture group doing the following
  • \\S{1,5} Match any non-whitespace character between 1 and 5 times
  • [ \\t]*? Match space or tab characters any number of times, but as few as possible (note in PCRE regex, this can be replaced with \\h*? to make it shorter)
  • \\S+ Match any non-whitespace character between one and unlimited times
• .* Match any character (except newline character assuming s modifier is off - it should be for this problem)
• $ Assert position at the end of a line

Answer 2

You can use a regex like this:

^\S{1,5} \S+|^\S+
or
^\S{1,5} ?\S*

Working demo

By the way, if you want to replace a full line with the shortened version, then you can use this regex instead:

(^\S{1,5} \S+|^\S+).*
or
(^\S{1,5} ?\S*).*

With the replacement string $1 or \\1 depending on your regex engine.

Working demo