new buffer[size] get_pcvar_string(cvar, buffer, charsmax(buffer)) //do something with buffer
This is more or less pseudocode, adapt it to your situation. The idea is you do not pass the size of a string manually, you use charsmax() to determine it automatically. This way, you don't pass a wrong value and if you ever change the string size then you do not need to change it in every function that uses it.
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