How get string inside bracket "()" using cmake regex-CodePudding

I am trying to get the string inside '( )' by using CMake regex. here is the example which I tried:

set(STR "example(arg1,arg2)")
string(REGEX MATCH "^\(.*\)$" ARG_STR ${STR})

expected: arg1,arg2, but I got example(arg1,arg2) Please guide me how to fix this.

CodePudding user response：

You can use a capturing group with a pattern lie

string(REGEX MATCH "\\(([^()]*)\\)" _ ${STR})

Then, you can access the contents using ${CMAKE_MATCH_1}, e.g.

message("ARGS_STR: ${CMAKE_MATCH_1}")

See CMAKE reference details:

New in version 3.9: All regular expression-related commands, including e.g. if(MATCHES), save subgroup matches in the variables CMAKE_MATCH_ for <n> 0..9.

Also, see the regex demo.

CodePudding user response：

The question was already answered correctly. But I'd like to show an easy way to also add error checking in case the regex fails.

set(STR "example(arg1,arg2)")

if (${STR} MATCHES "\\(([^()]*)\\)")
    message(STATUS ${CMAKE_MATCH_1})
else()
    message(FATAL_ERROR "Regex failed!")
endif()