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 /* advise calls advertise() with no tail to print fmt, and perhaps what,
  17  * to stderr. */
  18 void
  19 advise (const char *what, const char *fmt, ...)
  20 {
  21     va_list ap;
  22
  23     va_start(ap, fmt);
  24     advertise (what, NULL, fmt, ap);
  25     va_end(ap);
  26 }
  27
  28
  29 /* adios calls advertise() with no tail to print fmt, and perhaps what,
  30  * to stderr, and "ends" the program with an error exit status.  The
  31  * route to exit is via the done function pointer and may not be
  32  * straightforward.
  33  * FIXME: Document if this function can ever return.  If not, perhaps an
  34  * abort(3) at the end of the routine would make that more clear. */
  35 void
  36 adios (const char *what, const char *fmt, ...)
  37 {
  38     va_list ap;
  39
  40     va_start(ap, fmt);
  41     advertise (what, NULL, fmt, ap);
  42     va_end(ap);
  43     done (1);
  44 }
  45
  46
  47 /* admonish calls advertise() with a tail indicating the program
  48  * continues. */
  49 void
  50 admonish (char *what, char *fmt, ...)
  51 {
  52     va_list ap;
  53
  54     va_start(ap, fmt);
  55     advertise (what, "continuing...", fmt, ap);
  56     va_end(ap);
  57 }
  58
  59
  60 /* advertise prints fmt and ap to stderr after flushing stdout.
  61  * If invo_name isn't NULL or empty, it precedes the output seperated by ": ".
  62  * If what isn't NULL, errno as a string is appended.
  63  * A non-empty what separates fmt from errno, surrounded by " " and ": ".
  64  * BUG: No space separator before errno if what is "".
  65  * If tail isn't NULL or empty then ", " and tail are appended
  66  * before the finishing "\n".
  67  * In summary: "invo_name: fmt what: errno, tail\n". */
  68 void
  69 advertise (const char *what, char *tail, const char *fmt, va_list ap)
  70 {
  71     int eindex = errno;
  72     char buffer[NMH_BUFSIZ], errbuf[NMH_BUFSIZ], *err;
  73     struct iovec iob[10], *iov;
  74     size_t niov;
  75
  76     iov = iob;
  77
  78 #define APPEND_IOV(p, len) \
  79     iov->iov_base = (p); \
  80     iov->iov_len = (len); \
  81     iov++
  82
  83 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
  84 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
  85
  86     if (invo_name && *invo_name) {
  87         ADD_VAR(invo_name);
  88         ADD_LITERAL(": ");
  89     }
  90
  91     vsnprintf (buffer, sizeof(buffer), fmt, ap);
  92     ADD_VAR(buffer);
  93     if (what) {
  94         if (*what) {
  95             ADD_LITERAL(" ");
  96             ADD_VAR((void *)what);
  97             ADD_LITERAL(": ");
  98         }
  99         err = strerror(eindex);
 100         if (!err) {
 101             /* this shouldn't happen, but we'll test for it just in case */
 102             snprintf(errbuf, sizeof(errbuf), "Error %d", eindex);
 103             err = errbuf;
 104         }
 105         ADD_VAR(err);
 106     }
 107     if (tail && *tail) {
 108         ADD_LITERAL(", ");
 109         ADD_VAR(tail);
 110     }
 111     ADD_LITERAL("\n");
 112
 113 #undef ADD_LITERAL
 114 #undef ADD_VAR
 115
 116     niov = iov - iob;
 117     assert(niov <= DIM(iob));
 118
 119     fflush (stdout);
 120     fflush (stderr);
 121     if (writev(fileno(stderr), iob, niov) == -1) {
 122         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 123             invo_name && *invo_name ? invo_name : "nmh", errno);
 124         if (write(2, buffer, strlen(buffer)) == -1) {
 125             /* Ignore.  if-statement needed to shut up compiler. */
 126         }
 127     }
 128 }