CODEWITHSUNDEEP
regexcmake
Kennedy
Kennedy

Reputation: 317

CMake regex match

I have a CMake string variable:

set(var "String0 String_1 String_2")

I need to select whatever is before the first whitespace from this variable ("String0") and make a new variable with this content.

I used CMake's REGEX MATCH method to do this and used this regex: '\S\w*'. I have tested that regex on an online regex interpreter and it worked.

I have written this code in CMake (after setting the variable of course):

string(REGEX MATCH "\S\w*" NEW_VAR "${VAR}")

When I do this the script complains about invalid skipping of characters (S and w). So, next, I tried escaping both the slashes:

string(REGEX MATCH "\\S\\w*" NEW_VAR "${VAR}")

Now NEW_VAR equal 'S' instead of "String0" as I was expecting.

Please help me correct this, since I have very little experience with regular expressions and CMake.

Upvotes: 2

Views: 29329

Answers (2)

Kennedy
Kennedy

Reputation: 317

I have used this and it works(not sure how good it is for all cases, though):

.[(A-z)|(a-z)|(0-9)]*

Upvotes: 0

compor
compor

Reputation: 2339

You could also search for the location of the first occurrence of a whitespace character and select the substring from the start of this string till that position:

set(var "String_0 String_1 String_2")

string(FIND ${var} " " wsloc)
message(STATUS "position of first whitespace character: ${wsloc}")

string(SUBSTRING ${var} 0 ${wsloc} newvar)
message(STATUS "selected substring: \"${newvar}\"")

Upvotes: 3

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