### 14.4 How to check Libgcrypt’s configuration. ¶

Although `GCRYCTL_PRINT_CONFIG` can be used to print configuration options, it is sometimes necessary to check them in a program. This can be accomplished by using this function:

Function: `char *` gcry_get_config `(int mode, const char *what)` ¶

  This function returns a malloced string with colon delimited configure options. With a value of 0 for mode this string resembles the output of `GCRYCTL_PRINT_CONFIG`. However, if what is not `NULL`, only the line where the first field (e.g., "cpu-arch") matches what is returned.

  Other values than 0 for mode are not defined. The caller shall free the string using `gcry_free`. On error `NULL` is returned and `ERRNO` is set; if a value for what is unknown, `ERRNO` will be set to 0.