diplodocus.org Git - nmh/blob - sbr/error.c

   1 /* error.c -- main error handling routines
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include <h/mh.h>
   9
  10 #include <sys/types.h>
  11 #include <sys/uio.h>
  12
  13
  14 /* inform calls advertise() with no what and no tail.
  15  * Thus the simple "[invo_name: ]fmt\n" results. */
  16 void inform(char *fmt, ...)
  17 {
  18     va_list ap;
  19
  20     va_start(ap, fmt);
  21     advertise(NULL, NULL, fmt, ap);
  22     va_end(ap);
  23 }
  24
  25
  26 /* advise calls advertise() with no tail to print fmt, and perhaps what,
  27  * to stderr.
  28  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results. */
  29 void
  30 advise (const char *what, const char *fmt, ...)
  31 {
  32     va_list ap;
  33
  34     va_start(ap, fmt);
  35     advertise (what, NULL, fmt, ap);
  36     va_end(ap);
  37 }
  38
  39
  40 /* adios is the same as advise(), but then "ends" the program.
  41  * It calls advertise() with no tail to print fmt, and perhaps what, to
  42  * stderr, and exits the program with an error status.
  43  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results.
  44  * The route to exit is via the done function pointer and may not be
  45  * straightforward, e.g. longjmp(3), but it must not return to adios().
  46  * If it does then it's a bug and adios() will abort(3) as callers do
  47  * not expect execution to continue. */
  48 void NORETURN
  49 adios (const char *what, const char *fmt, ...)
  50 {
  51     va_list ap;
  52
  53     va_start(ap, fmt);
  54     advertise (what, NULL, fmt, ap);
  55     va_end(ap);
  56     done (1);
  57     abort();
  58 }
  59
  60
  61 /* admonish calls advertise() with a tail indicating the program
  62  * continues.
  63  * Thus "[invo_name: ]fmt[[ what]: errno], continuing...\n" results. */
  64 void
  65 admonish (char *what, char *fmt, ...)
  66 {
  67     va_list ap;
  68
  69     va_start(ap, fmt);
  70     advertise (what, "continuing...", fmt, ap);
  71     va_end(ap);
  72 }
  73
  74
  75 /* advertise prints fmt and ap to stderr after flushing stdout.
  76  * If invo_name isn't NULL or empty then "invo_name: " precedes fmt.
  77  * If what isn't NULL or empty      then " what"   is appended.
  78  * If what isn't NULL               then ": errno" is appended.
  79  * If tail isn't NULL or empty      then ", tail"  is appended.
  80  * A "\n" finishes the output to stderr.
  81  * In summary: "[invo_name: ]fmt[[ what]: errno][, tail]\n". */
  82 void
  83 advertise (const char *what, char *tail, const char *fmt, va_list ap)
  84 {
  85     int eindex = errno;
  86     char buffer[NMH_BUFSIZ], *err;
  87     struct iovec iob[10], *iov;
  88     size_t niov;
  89
  90     iov = iob;
  91
  92 #define APPEND_IOV(p, len) \
  93     iov->iov_base = (p); \
  94     iov->iov_len = (len); \
  95     iov++
  96
  97 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
  98 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
  99
 100     if (invo_name && *invo_name) {
 101         ADD_VAR(invo_name);
 102         ADD_LITERAL(": ");
 103     }
 104
 105     vsnprintf (buffer, sizeof(buffer), fmt, ap);
 106     ADD_VAR(buffer);
 107     if (what) {
 108         if (*what) {
 109             ADD_LITERAL(" ");
 110             ADD_VAR((void *)what);
 111         }
 112         ADD_LITERAL(": ");
 113         err = strerror(eindex);
 114         ADD_VAR(err);
 115     }
 116     if (tail && *tail) {
 117         ADD_LITERAL(", ");
 118         ADD_VAR(tail);
 119     }
 120     ADD_LITERAL("\n");
 121
 122 #undef ADD_LITERAL
 123 #undef ADD_VAR
 124
 125     niov = iov - iob;
 126     assert(niov <= DIM(iob));
 127
 128     fflush (stdout);
 129     fflush (stderr);
 130     if (writev(fileno(stderr), iob, niov) == -1) {
 131         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 132             invo_name && *invo_name ? invo_name : "nmh", errno);
 133         if (write(2, buffer, strlen(buffer)) == -1) {
 134             /* Ignore.  if-statement needed to shut up compiler. */
 135         }
 136     }
 137 }