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

   1
   2 /*
   3  * error.c -- main error handling routines
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11
  12 #include <sys/types.h>
  13 #include <sys/uio.h>
  14
  15
  16 /* inform calls advertise() with no what and no tail.
  17  * Thus the simple "[invo_name: ]fmt\n" results. */
  18 void inform(char *fmt, ...)
  19 {
  20     va_list ap;
  21
  22     va_start(ap, fmt);
  23     advertise(NULL, NULL, fmt, ap);
  24     va_end(ap);
  25 }
  26
  27
  28 /* advise calls advertise() with no tail to print fmt, and perhaps what,
  29  * to stderr.
  30  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results. */
  31 void
  32 advise (const char *what, const char *fmt, ...)
  33 {
  34     va_list ap;
  35
  36     va_start(ap, fmt);
  37     advertise (what, NULL, fmt, ap);
  38     va_end(ap);
  39 }
  40
  41
  42 /* adios is the same as advise(), but then "ends" the program.
  43  * It calls advertise() with no tail to print fmt, and perhaps what, to
  44  * stderr, and exits the program with an error status.
  45  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results.
  46  * The route to exit is via the done function pointer and may not be
  47  * straightforward, e.g. longjmp(3), but it must not return to adios().
  48  * If it does then it's a bug and adios() will abort(3) as callers do
  49  * not expect execution to continue. */
  50 void
  51 adios (const char *what, const char *fmt, ...)
  52 {
  53     va_list ap;
  54
  55     va_start(ap, fmt);
  56     advertise (what, NULL, fmt, ap);
  57     va_end(ap);
  58     done (1);
  59     abort();
  60 }
  61
  62
  63 /* admonish calls advertise() with a tail indicating the program
  64  * continues.
  65  * Thus "[invo_name: ]fmt[[ what]: errno], continuing...\n" results. */
  66 void
  67 admonish (char *what, char *fmt, ...)
  68 {
  69     va_list ap;
  70
  71     va_start(ap, fmt);
  72     advertise (what, "continuing...", fmt, ap);
  73     va_end(ap);
  74 }
  75
  76
  77 /* advertise prints fmt and ap to stderr after flushing stdout.
  78  * If invo_name isn't NULL or empty then "invo_name: " precedes fmt.
  79  * If what isn't NULL or empty      then " what"   is appended.
  80  * If what isn't NULL               then ": errno" is appended.
  81  * If tail isn't NULL or empty      then ", tail"  is appended.
  82  * A "\n" finishes the output to stderr.
  83  * In summary: "[invo_name: ]fmt[[ what]: errno][, tail]\n". */
  84 void
  85 advertise (const char *what, char *tail, const char *fmt, va_list ap)
  86 {
  87     int eindex = errno;
  88     char buffer[NMH_BUFSIZ], *err;
  89     struct iovec iob[10], *iov;
  90     size_t niov;
  91
  92     iov = iob;
  93
  94 #define APPEND_IOV(p, len) \
  95     iov->iov_base = (p); \
  96     iov->iov_len = (len); \
  97     iov++
  98
  99 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
 100 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
 101
 102     if (invo_name && *invo_name) {
 103         ADD_VAR(invo_name);
 104         ADD_LITERAL(": ");
 105     }
 106
 107     vsnprintf (buffer, sizeof(buffer), fmt, ap);
 108     ADD_VAR(buffer);
 109     if (what) {
 110         if (*what) {
 111             ADD_LITERAL(" ");
 112             ADD_VAR((void *)what);
 113         }
 114         ADD_LITERAL(": ");
 115         err = strerror(eindex);
 116         ADD_VAR(err);
 117     }
 118     if (tail && *tail) {
 119         ADD_LITERAL(", ");
 120         ADD_VAR(tail);
 121     }
 122     ADD_LITERAL("\n");
 123
 124 #undef ADD_LITERAL
 125 #undef ADD_VAR
 126
 127     niov = iov - iob;
 128     assert(niov <= DIM(iob));
 129
 130     fflush (stdout);
 131     fflush (stderr);
 132     if (writev(fileno(stderr), iob, niov) == -1) {
 133         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 134             invo_name && *invo_name ? invo_name : "nmh", errno);
 135         if (write(2, buffer, strlen(buffer)) == -1) {
 136             /* Ignore.  if-statement needed to shut up compiler. */
 137         }
 138     }
 139 }