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, e.g. longjmp(3), but it must not return to adios().
  33  * If it does then it's a bug and adios() will abort(3) as callers do
  34  * not expect execution to continue. */
  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     abort();
  45 }
  46
  47
  48 /* admonish calls advertise() with a tail indicating the program
  49  * continues. */
  50 void
  51 admonish (char *what, char *fmt, ...)
  52 {
  53     va_list ap;
  54
  55     va_start(ap, fmt);
  56     advertise (what, "continuing...", fmt, ap);
  57     va_end(ap);
  58 }
  59
  60
  61 /* advertise prints fmt and ap to stderr after flushing stdout.
  62  * If invo_name isn't NULL or empty, it precedes the output seperated by ": ".
  63  * If what isn't NULL, errno as a string is appended.
  64  * A non-empty what separates fmt from errno, surrounded by " " and ": ".
  65  * BUG: No space separator before errno if what is "".
  66  * If tail isn't NULL or empty then ", " and tail are appended
  67  * before the finishing "\n".
  68  * In summary: "invo_name: fmt what: errno, tail\n". */
  69 void
  70 advertise (const char *what, char *tail, const char *fmt, va_list ap)
  71 {
  72     int eindex = errno;
  73     char buffer[NMH_BUFSIZ], errbuf[NMH_BUFSIZ], *err;
  74     struct iovec iob[10], *iov;
  75     size_t niov;
  76
  77     iov = iob;
  78
  79 #define APPEND_IOV(p, len) \
  80     iov->iov_base = (p); \
  81     iov->iov_len = (len); \
  82     iov++
  83
  84 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
  85 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
  86
  87     if (invo_name && *invo_name) {
  88         ADD_VAR(invo_name);
  89         ADD_LITERAL(": ");
  90     }
  91
  92     vsnprintf (buffer, sizeof(buffer), fmt, ap);
  93     ADD_VAR(buffer);
  94     if (what) {
  95         if (*what) {
  96             ADD_LITERAL(" ");
  97             ADD_VAR((void *)what);
  98             ADD_LITERAL(": ");
  99         }
 100         err = strerror(eindex);
 101         if (!err) {
 102             /* this shouldn't happen, but we'll test for it just in case */
 103             snprintf(errbuf, sizeof(errbuf), "Error %d", eindex);
 104             err = errbuf;
 105         }
 106         ADD_VAR(err);
 107     }
 108     if (tail && *tail) {
 109         ADD_LITERAL(", ");
 110         ADD_VAR(tail);
 111     }
 112     ADD_LITERAL("\n");
 113
 114 #undef ADD_LITERAL
 115 #undef ADD_VAR
 116
 117     niov = iov - iob;
 118     assert(niov <= DIM(iob));
 119
 120     fflush (stdout);
 121     fflush (stderr);
 122     if (writev(fileno(stderr), iob, niov) == -1) {
 123         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 124             invo_name && *invo_name ? invo_name : "nmh", errno);
 125         if (write(2, buffer, strlen(buffer)) == -1) {
 126             /* Ignore.  if-statement needed to shut up compiler. */
 127         }
 128     }
 129 }