ESP8266 Community Forum

I have been searching and trying to figure this out, but I can't seem to find an answer. I am trying to use "strcasestr" with the ESP8266 in Arduino IDE. When compiling, I am getting this error "undefined reference to `strcasestr'". This error does not occur when using "strstr", only "strcasestr". This error also does not occur when I select Arduino boards, only occurs on ESP8266 boards.

I have checked the ESP8266 strings.h file and the "strcasestr" entry exists in it. I have also tried this solution https://stackoverflow.com/questions/9935642/how-do-i-use-strcasestr, but it doesn't seem to work either.

Could anyone kindly assist on the issue.

Undefined reference means it's not in the library, it shouldn't be in strings.h. It's easy to write your own.