external/ibm-public/postfix/dist/src/util/split_nameval.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      split_nameval 3
   6 /* SUMMARY
   7 /*      name-value splitter
   8 /* SYNOPSIS
   9 /*      #include <split_nameval.h>
  10 /*
  11 /*      const char *split_nameval(buf, name, value)
  12 /*      char    *buf;
  13 /*      char    **name;
  14 /*      char    **value;
  15 /* DESCRIPTION
  16 /*      split_nameval() takes a logical line from readlline() and expects
  17 /*      text of the form "name = value" or "name =". The buffer
  18 /*      argument is broken up into name and value substrings.
  19 /*
  20 /*      Arguments:
  21 /* .IP buf
  22 /*      Result from readlline() or equivalent. The buffer is modified.
  23 /* .IP name
  24 /*      Upon successful completion, this is set to the name
  25 /*      substring.
  26 /* .IP value
  27 /*      Upon successful completion, this is set to the value
  28 /*      substring.
  29 /* FEATURES
  30 /* SEE ALSO
  31 /*      dict(3) mid-level dictionary routines
  32 /* BUGS
  33 /* DIAGNOSTICS
  34 /*      Fatal errors: out of memory.
  35 /*
  36 /*      The result is a null pointer in case of success, a string
  37 /*      describing the error otherwise: missing '=' after attribute
  38 /*      name; missing attribute name.
  39 /* LICENSE
  40 /* .ad
  41 /* .fi
  42 /*      The Secure Mailer license must be distributed with this software.
  43 /* AUTHOR(S)
  44 /*      Wietse Venema
  45 /*      IBM T.J. Watson Research
  46 /*      P.O. Box 704
  47 /*      Yorktown Heights, NY 10598, USA
  48 /*--*/
  49
  50 /* System libraries. */
  51
  52 #include "sys_defs.h"
  53 #include <ctype.h>
  54 #include <string.h>
  55
  56 /* Utility library. */
  57
  58 #include <msg.h>
  59 #include <stringops.h>
  60
  61 /* split_nameval - split text into name and value */
  62
  63 const char *split_nameval(char *buf, char **name, char **value)
  64 {
  65     char   *np;                         /* name substring */
  66     char   *vp;                         /* value substring */
  67     char   *cp;
  68     char   *ep;
  69
  70     /*
  71      * Ugly macros to make complex expressions less unreadable.
  72      */
  73 #define SKIP(start, var, cond) \
  74         for (var = start; *var && (cond); var++);
  75
  76 #define TRIM(s) { \
  77         char *p; \
  78         for (p = (s) + strlen(s); p > (s) && ISSPACE(p[-1]); p--); \
  79         *p = 0; \
  80     }
  81
  82     SKIP(buf, np, ISSPACE(*np));                /* find name begin */
  83     if (*np == 0)
  84         return ("missing attribute name");
  85     SKIP(np, ep, !ISSPACE(*ep) && *ep != '=');  /* find name end */
  86     SKIP(ep, cp, ISSPACE(*cp));                 /* skip blanks before '=' */
  87     if (*cp != '=')                             /* need '=' */
  88         return ("missing '=' after attribute name");
  89     *ep = 0;                                    /* terminate name */
  90     cp++;                                       /* skip over '=' */
  91     SKIP(cp, vp, ISSPACE(*vp));                 /* skip leading blanks */
  92     TRIM(vp);                                   /* trim trailing blanks */
  93     *name = np;
  94     *value = vp;
  95     return (0);
  96 }