lib/libsys/env_parse.c

   1 #include "sysutil.h"
   2 #include <stdlib.h>
   3 #include <env.h>
   4 #include <string.h>
   5 #include <minix/param.h>
   6
   7
   8 /*=========================================================================*
   9  *                              env_parse                                  *
  10  *=========================================================================*/
  11 int env_parse(env, fmt, field, param, min, max)
  12 char *env;              /* environment variable to inspect */
  13 char *fmt;              /* template to parse it with */
  14 int field;              /* field number of value to return */
  15 long *param;            /* address of parameter to get */
  16 long min, max;          /* minimum and maximum values for the parameter */
  17 {
  18 /* Parse an environment variable setting, something like "DPETH0=300:3".
  19  * Panic if the parsing fails.  Return EP_UNSET if the environment variable
  20  * is not set, EP_OFF if it is set to "off", EP_ON if set to "on" or a
  21  * field is left blank, or EP_SET if a field is given (return value through
  22  * *param).  Punctuation may be used in the environment and format string,
  23  * fields in the environment string may be empty, and punctuation may be
  24  * missing to skip fields.  The format string contains characters 'd', 'o',
  25  * 'x' and 'c' to indicate that 10, 8, 16, or 0 is used as the last argument
  26  * to strtol().  A '*' means that a field should be skipped.  If the format
  27  * string contains something like "\4" then the string is repeated 4 characters
  28  * to the left.
  29  */
  30   char *val, *end;
  31   char value[EP_BUF_SIZE];
  32   char PUNCT[] = ":,;.";
  33   long newpar;
  34   int s, i, radix, r;
  35
  36   if ((s=env_get_param(env, value, sizeof(value))) != 0) {
  37       if (s == ESRCH) return(EP_UNSET);         /* only error allowed */
  38       printf("WARNING: env_get_param() failed in env_parse(): %d\n",s);
  39       return(EP_EGETKENV);
  40   }
  41   val = value;
  42   if (strcmp(val, "off") == 0) return(EP_OFF);
  43   if (strcmp(val, "on") == 0) return(EP_ON);
  44
  45   i = 0;
  46   r = EP_ON;
  47   for (;;) {
  48         while (*val == ' ') val++;      /* skip spaces */
  49         if (*val == 0) return(r);       /* the proper exit point */
  50         if (*fmt == 0) break;           /* too many values */
  51
  52         if (strchr(PUNCT, *val) != NULL) {
  53                 /* Time to go to the next field. */
  54                 if (strchr(PUNCT, *fmt) != NULL) i++;
  55                 if (*fmt++ == *val) val++;
  56                 if (*fmt < 32) fmt -= *fmt;     /* step back? */
  57         } else {
  58                 /* Environment contains a value, get it. */
  59                 switch (*fmt) {
  60                 case '*':       radix =   -1;   break;
  61                 case 'd':       radix =   10;   break;
  62                 case 'o':       radix =  010;   break;
  63                 case 'x':       radix = 0x10;   break;
  64                 case 'c':       radix =    0;   break;
  65                 default:        goto badenv;
  66                 }
  67
  68                 if (radix < 0) {
  69                         /* Skip. */
  70                         while (strchr(PUNCT, *val) == NULL) val++;
  71                         continue;
  72                 } else {
  73                         /* A number. */
  74                         newpar = strtol(val, &end, radix);
  75
  76                         if (end == val) break;  /* not a number */
  77                         val = end;
  78                 }
  79
  80                 if (i == field) {
  81                         /* The field requested. */
  82                         if (newpar < min || newpar > max) break;
  83                         *param = newpar;
  84                         r = EP_SET;
  85                 }
  86         }
  87   }
  88 badenv:
  89   env_panic(env);
  90   return -1;
  91 }
  92
  93 /*=========================================================================*
  94  *                              env_memory_parse                           *
  95  *=========================================================================*/
  96
  97 int env_memory_parse(mem_chunks, maxchunks)
  98 struct memory *mem_chunks;      /* where to store the memory bits */
  99 int maxchunks;                  /* how many were found */
 100 {
 101   static kinfo_t kinfo;
 102   int mm, r;
 103
 104   if((r=sys_getkinfo(&kinfo)) != OK) return r;
 105
 106   /* Initialize everything to zero. */
 107   memset(mem_chunks, 0, maxchunks*sizeof(*mem_chunks));
 108
 109   for(mm = 0; mm < MAXMEMMAP; mm++) {
 110         mem_chunks[mm].base = kinfo.memmap[mm].addr;
 111         mem_chunks[mm].size = kinfo.memmap[mm].len;
 112   }
 113
 114   return OK;
 115 }