Functions HI-TECH C PERROR
#include <stdio.h> void perror(char * s)
This routine will print on the stderr stream the argument s, followed by a descriptive message detailing the last error returned from an open, close read or write call. Unfortunately CP/M does not provide definitive information relating to the error, except in the case of a random read or write. Thus this routine is of limited usefulness under CP/M. MS-DOS provides much more information however, and use of perror() after MS-DOS file handling calls will certainly give useful diagnostics.
open, close, read, write