4.25 Miscellaneous functions

Function: strerror errno

Return a string describing the errno code errno. Makes use of the system function strerror(). If errno is not a valid errno value: return a string telling it. As special cases errno can be also #t, meaning “unknown error”, and #f, meaning “no error”.

(libc)Error Messages

Function: file-descriptor? obj

Return true if obj is a non–negative fixnum less than the value of FD_SETSIZE.

Function: network-port-number? obj

Return true if obj is a fixnum integer in the range of network ports [1, 65535].