CRTL, confstr, Return Values
*Conan The Librarian
0 Indicates an error. When the specified name value: o Is invalid, errno is set to EINVAL. o Does not have a system-defined value, errno is not set. n The size of the buffer needed to hold the value. o When the value of the name argument is system-defined, confstr returns the size of the buffer needed to hold the entire value. If this return value is greater than the len value, the string returned as the buf value is truncated. o When the value of the len argument is set to 0 or the buf value is NULL, confstr returns the size of the buffer needed to hold the entire system-defined value. The string value is not copied.