src/regex/regerror.c

   1 /*
   2  * regerror - error-code expansion
   3  *
   4  * Copyright (c) 1998, 1999 Henry Spencer.  All rights reserved.
   5  *
   6  * Development of this software was funded, in part, by Cray Research Inc.,
   7  * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
   8  * Corporation, none of whom are responsible for the results.  The author
   9  * thanks all of them.
  10  *
  11  * Redistribution and use in source and binary forms -- with or without
  12  * modification -- are permitted for any purpose, provided that
  13  * redistributions in source form retain this entire copyright notice and
  14  * indicate the origin and nature of any modifications.
  15  *
  16  * I'd appreciate being given credit for this package in the documentation
  17  * of software which uses it, but that is not a requirement.
  18  *
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  22  * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  */
  31
  32 #include "regguts.h"
  33
  34 /* unknown-error explanation */
  35 static char unk[] = "*** unknown regex error code 0x%x ***";
  36
  37 /* struct to map among codes, code names, and explanations */
  38 static struct rerr {
  39         int code;
  40         char *name;
  41         char *explain;
  42 } rerrs[] = {
  43         /* the actual table is built from regex.h */
  44 #       include "regerrs.h"
  45         { -1,   "",     "oops" },       /* explanation special-cased in code */
  46 };
  47
  48 /*
  49  - regerror - the interface to error numbers
  50  */
  51 /* ARGSUSED */
  52 size_t                          /* actual space needed (including NUL) */
  53 regerror(errcode, preg, errbuf, errbuf_size)
  54 int errcode;                    /* error code, or REG_ATOI or REG_ITOA */
  55 CONST regex_t *preg;            /* associated regex_t (unused at present) */
  56 char *errbuf;                   /* result buffer (unless errbuf_size==0) */
  57 size_t errbuf_size;             /* available space in errbuf, can be 0 */
  58 {
  59         struct rerr *r;
  60         char *msg;
  61         char convbuf[sizeof(unk)+50];   /* 50 = plenty for int */
  62         size_t len;
  63         int icode;
  64
  65         switch (errcode) {
  66         case REG_ATOI:          /* convert name to number */
  67                 for (r = rerrs; r->code >= 0; r++)
  68                         if (strcmp(r->name, errbuf) == 0)
  69                                 break;
  70                 sprintf(convbuf, "%d", r->code);        /* -1 for unknown */
  71                 msg = convbuf;
  72                 break;
  73         case REG_ITOA:          /* convert number to name */
  74                 icode = atoi(errbuf);   /* not our problem if this fails */
  75                 for (r = rerrs; r->code >= 0; r++)
  76                         if (r->code == icode)
  77                                 break;
  78                 if (r->code >= 0)
  79                         msg = r->name;
  80                 else {                  /* unknown; tell him the number */
  81                         sprintf(convbuf, "REG_%u", (unsigned)icode);
  82                         msg = convbuf;
  83                 }
  84                 break;
  85         default:                /* a real, normal error code */
  86                 for (r = rerrs; r->code >= 0; r++)
  87                         if (r->code == errcode)
  88                                 break;
  89                 if (r->code >= 0)
  90                         msg = r->explain;
  91                 else {                  /* unknown; say so */
  92                         sprintf(convbuf, unk, errcode);
  93                         msg = convbuf;
  94                 }
  95                 break;
  96         }
  97
  98         len = strlen(msg) + 1;          /* space needed, including NUL */
  99         if (errbuf_size > 0) {
 100                 if (errbuf_size > len)
 101                         strcpy(errbuf, msg);
 102                 else {                  /* truncate to fit */
 103                         strncpy(errbuf, msg, errbuf_size-1);
 104                         errbuf[errbuf_size-1] = '\0';
 105                 }
 106         }
 107
 108         return len;
 109 }