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 #include "h/done.h"
  13
  14 /* inform calls advertise() with no what and no tail.
  15  * Thus the simple "[invo_name: ]fmt\n" results. */
  16 void
  17 inform(char *fmt, ...)
  18 {
  19     va_list ap;
  20
  21     va_start(ap, fmt);
  22     advertise(NULL, NULL, fmt, ap);
  23     va_end(ap);
  24 }
  25
  26
  27 /* advise calls advertise() with no tail to print fmt, and perhaps what,
  28  * to stderr.
  29  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results. */
  30 void
  31 advise (const char *what, const char *fmt, ...)
  32 {
  33     va_list ap;
  34
  35     va_start(ap, fmt);
  36     advertise (what, NULL, fmt, ap);
  37     va_end(ap);
  38 }
  39
  40
  41 /* adios is the same as advise(), but then "ends" the program.
  42  * It calls advertise() with no tail to print fmt, and perhaps what, to
  43  * stderr, and exits the program with an error status.
  44  * Thus "[invo_name: ]fmt[[ what]: errno]\n" results.
  45  * The route to exit is via the done function pointer and may not be
  46  * straightforward, e.g. longjmp(3), but it must not return to adios().
  47  * If it does then it's a bug and adios() will abort(3) as callers do
  48  * not expect execution to continue. */
  49 void NORETURN
  50 adios (const char *what, const char *fmt, ...)
  51 {
  52     va_list ap;
  53
  54     va_start(ap, fmt);
  55     advertise (what, NULL, fmt, ap);
  56     va_end(ap);
  57     done (1);
  58     abort();
  59 }
  60
  61
  62 /* die is the same as adios(), but without the what as that's commonly
  63  * NULL. */
  64 void NORETURN
  65 die(const char *fmt, ...)
  66 {
  67     va_list ap;
  68
  69     va_start(ap, fmt);
  70     advertise(NULL, NULL, fmt, ap);
  71     va_end(ap);
  72     done(1);
  73     abort();
  74 }
  75
  76
  77 /* admonish calls advertise() with a tail indicating the program
  78  * continues.
  79  * Thus "[invo_name: ]fmt[[ what]: errno], continuing...\n" results. */
  80 void
  81 admonish (char *what, char *fmt, ...)
  82 {
  83     va_list ap;
  84
  85     va_start(ap, fmt);
  86     advertise (what, "continuing...", fmt, ap);
  87     va_end(ap);
  88 }
  89
  90
  91 /* advertise prints fmt and ap to stderr after flushing stdout.
  92  * If invo_name isn't NULL or empty then "invo_name: " precedes fmt.
  93  * If what isn't NULL or empty      then " what"   is appended.
  94  * If what isn't NULL               then ": errno" is appended.
  95  * If tail isn't NULL or empty      then ", tail"  is appended.
  96  * A "\n" finishes the output to stderr.
  97  * In summary: "[invo_name: ]fmt[[ what]: errno][, tail]\n". */
  98 void
  99 advertise (const char *what, char *tail, const char *fmt, va_list ap)
 100 {
 101     int eindex = errno;
 102     char buffer[NMH_BUFSIZ], *err;
 103     struct iovec iob[10], *iov;
 104     size_t niov;
 105
 106     iov = iob;
 107
 108 #define APPEND_IOV(p, len) \
 109     iov->iov_base = (p); \
 110     iov->iov_len = (len); \
 111     iov++
 112
 113 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
 114 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
 115
 116     if (invo_name && *invo_name) {
 117         ADD_VAR(invo_name);
 118         ADD_LITERAL(": ");
 119     }
 120
 121     vsnprintf (buffer, sizeof(buffer), fmt, ap);
 122     ADD_VAR(buffer);
 123     if (what) {
 124         if (*what) {
 125             ADD_LITERAL(" ");
 126             ADD_VAR((void *)what);
 127         }
 128         ADD_LITERAL(": ");
 129         err = strerror(eindex);
 130         ADD_VAR(err);
 131     }
 132     if (tail && *tail) {
 133         ADD_LITERAL(", ");
 134         ADD_VAR(tail);
 135     }
 136     ADD_LITERAL("\n");
 137
 138 #undef ADD_LITERAL
 139 #undef ADD_VAR
 140
 141     niov = iov - iob;
 142     assert(niov <= DIM(iob));
 143
 144     fflush (stdout);
 145     fflush (stderr);
 146     if (writev(fileno(stderr), iob, niov) == -1) {
 147         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 148             invo_name && *invo_name ? invo_name : "nmh", errno);
 149         if (write(2, buffer, strlen(buffer)) == -1) {
 150             /* Ignore.  if-statement needed to shut up compiler. */
 151         }
 152     }
 153 }