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 #include "error.h"
  10
  11 #include <sys/types.h>
  12 #include <sys/uio.h>
  13 #include "h/done.h"
  14
  15 /* inform calls advertise() with no what and no tail.
  16  * Thus the simple "[invo_name: ]fmt\n" results. */
  17 void
  18 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 NORETURN
  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 /* die is the same as adios(), but without the what as that's commonly
  64  * NULL. */
  65 void NORETURN
  66 die(const char *fmt, ...)
  67 {
  68     va_list ap;
  69
  70     va_start(ap, fmt);
  71     advertise(NULL, NULL, fmt, ap);
  72     va_end(ap);
  73     done(1);
  74     abort();
  75 }
  76
  77
  78 /* admonish calls advertise() with a tail indicating the program
  79  * continues.
  80  * Thus "[invo_name: ]fmt[[ what]: errno], continuing...\n" results. */
  81 void
  82 admonish (char *what, char *fmt, ...)
  83 {
  84     va_list ap;
  85
  86     va_start(ap, fmt);
  87     advertise (what, "continuing...", fmt, ap);
  88     va_end(ap);
  89 }
  90
  91
  92 /* advertise prints fmt and ap to stderr after flushing stdout.
  93  * If invo_name isn't NULL or empty then "invo_name: " precedes fmt.
  94  * If what isn't NULL or empty      then " what"   is appended.
  95  * If what isn't NULL               then ": errno" is appended.
  96  * If tail isn't NULL or empty      then ", tail"  is appended.
  97  * A "\n" finishes the output to stderr.
  98  * In summary: "[invo_name: ]fmt[[ what]: errno][, tail]\n". */
  99 void
 100 advertise (const char *what, char *tail, const char *fmt, va_list ap)
 101 {
 102     int eindex = errno;
 103     char buffer[NMH_BUFSIZ], *err;
 104     struct iovec iob[10], *iov;
 105     size_t niov;
 106
 107     iov = iob;
 108
 109 #define APPEND_IOV(p, len) \
 110     iov->iov_base = (p); \
 111     iov->iov_len = (len); \
 112     iov++
 113
 114 #define ADD_LITERAL(s) APPEND_IOV((s), LEN(s))
 115 #define ADD_VAR(s) APPEND_IOV((s), strlen(s))
 116
 117     if (invo_name && *invo_name) {
 118         ADD_VAR(invo_name);
 119         ADD_LITERAL(": ");
 120     }
 121
 122     vsnprintf (buffer, sizeof(buffer), fmt, ap);
 123     ADD_VAR(buffer);
 124     if (what) {
 125         if (*what) {
 126             ADD_LITERAL(" ");
 127             ADD_VAR((void *)what);
 128         }
 129         ADD_LITERAL(": ");
 130         err = strerror(eindex);
 131         ADD_VAR(err);
 132     }
 133     if (tail && *tail) {
 134         ADD_LITERAL(", ");
 135         ADD_VAR(tail);
 136     }
 137     ADD_LITERAL("\n");
 138
 139 #undef ADD_LITERAL
 140 #undef ADD_VAR
 141
 142     niov = iov - iob;
 143     assert(niov <= DIM(iob));
 144
 145     fflush (stdout);
 146     fflush (stderr);
 147     if (writev(fileno(stderr), iob, niov) == -1) {
 148         snprintf(buffer, sizeof buffer, "%s: write stderr failed: %d\n",
 149             invo_name && *invo_name ? invo_name : "nmh", errno);
 150         if (write(2, buffer, strlen(buffer)) == -1) {
 151             /* Ignore.  if-statement needed to shut up compiler. */
 152         }
 153     }
 154 }