src/port/pgstrsignal.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pgstrsignal.c
   4  *        Identify a Unix signal number
   5  *
   6  * On platforms compliant with modern POSIX, this just wraps strsignal(3).
   7  * Elsewhere, we do the best we can.
   8  *
   9  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
  10  * Portions Copyright (c) 1994, Regents of the University of California
  11  *
  12  * IDENTIFICATION
  13  *        src/port/pgstrsignal.c
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17
  18 #include "c.h"
  19
  20
  21 /*
  22  * pg_strsignal
  23  *
  24  * Return a string identifying the given Unix signal number.
  25  *
  26  * The result is declared "const char *" because callers should not
  27  * modify the string.  Note, however, that POSIX does not promise that
  28  * the string will remain valid across later calls to strsignal().
  29  *
  30  * This version guarantees to return a non-NULL pointer, although
  31  * some platforms' versions of strsignal() reputedly do not.
  32  *
  33  * Note that the fallback cases just return constant strings such as
  34  * "unrecognized signal".  Project style is for callers to print the
  35  * numeric signal value along with the result of this function, so
  36  * there's no need to work harder than that.
  37  */
  38 const char *
  39 pg_strsignal(int signum)
  40 {
  41         const char *result;
  42
  43         /*
  44          * If we have strsignal(3), use that --- but check its result for NULL.
  45          */
  46 #ifdef HAVE_STRSIGNAL
  47         result = strsignal(signum);
  48         if (result == NULL)
  49                 result = "unrecognized signal";
  50 #else
  51
  52         /*
  53          * We used to have code here to try to use sys_siglist[] if available.
  54          * However, it seems that all platforms with sys_siglist[] have also had
  55          * strsignal() for many years now, so that was just a waste of code.
  56          */
  57         result = "(signal names not available on this platform)";
  58 #endif
  59
  60         return result;
  61 }