/* xstrerror.c -- jacket routine for more robust strerror() usage. Fri Jun 16 18:30:00 1995 Pat Rankin <rankin@eql.caltech.edu> This code is in the public domain. */ /* @deftypefn Replacement char* xstrerror (int @var{errnum}) Behaves exactly like the standard @code{strerror} function, but will never return a @code{NULL} pointer. @end deftypefn */ #include <stdio.h> #include "libiberty.h" #include "config.h" #ifdef VMS #include <errno.h> #if !defined (__STRICT_ANSI__) && !defined (__HIDE_FORBIDDEN_NAMES) extern char *strerror PARAMS ((int,...)); #define DONT_DECLARE_STRERROR #endif #endif /* VMS */ #ifndef DONT_DECLARE_STRERROR extern char *strerror PARAMS ((int)); #endif /* If strerror returns NULL, we'll format the number into a static buffer. */ #define ERRSTR_FMT "undocumented error #%d" static char xstrerror_buf[sizeof ERRSTR_FMT + 20]; /* Like strerror, but result is never a null pointer. */ char * xstrerror (errnum) int errnum; { char *errstr; #ifdef VMS char *(*vmslib_strerror) PARAMS ((int,...)); /* Override any possibly-conflicting declaration from system header. */ vmslib_strerror = (char *(*) PARAMS ((int,...))) strerror; /* Second argument matters iff first is EVMSERR, but it's simpler to pass it unconditionally. `vaxc$errno' is declared in <errno.h> and maintained by the run-time library in parallel to `errno'. We assume that `errnum' corresponds to the last value assigned to errno by the run-time library, hence vaxc$errno will be relevant. */ errstr = (*vmslib_strerror) (errnum, vaxc$errno); #else errstr = strerror (errnum); #endif /* If `errnum' is out of range, result might be NULL. We'll fix that. */ if (!errstr) { sprintf (xstrerror_buf, ERRSTR_FMT, errnum); errstr = xstrerror_buf; } return errstr; }