1 #include "sysutil.h" 2 #include <stdlib.h> 3 #include <string.h> 4 #include <minix/param.h> 5 6 7 /*=========================================================================* 8 * env_parse * 9 *=========================================================================*/ 10 int env_parse(const char *env, const char *fmt, 11 int field, long *param, long min, long max) 12 { 13 /* Parse an environment variable setting, something like "DPETH0=300:3". 14 * Panic if the parsing fails. Return EP_UNSET if the environment variable 15 * is not set, EP_OFF if it is set to "off", EP_ON if set to "on" or a 16 * field is left blank, or EP_SET if a field is given (return value through 17 * *param). Punctuation may be used in the environment and format string, 18 * fields in the environment string may be empty, and punctuation may be 19 * missing to skip fields. The format string contains characters 'd', 'o', 20 * 'x' and 'c' to indicate that 10, 8, 16, or 0 is used as the last argument 21 * to strtol(). A '*' means that a field should be skipped. If the format 22 * string contains something like "\4" then the string is repeated 4 characters 23 * to the left. 24 */ 25 char *val, *end; 26 char value[EP_BUF_SIZE]; 27 char PUNCT[] = ":,;."; 28 long newpar; 29 int s, i, radix, r; 30 31 if ((s=env_get_param(env, value, sizeof(value))) != 0) { 32 if (s == ESRCH) return(EP_UNSET); /* only error allowed */ 33 printf("WARNING: env_get_param() failed in env_parse(): %d\n",s); 34 return(EP_EGETKENV); 35 } 36 val = value; 37 if (strcmp(val, "off") == 0) return(EP_OFF); 38 if (strcmp(val, "on") == 0) return(EP_ON); 39 40 i = 0; 41 r = EP_ON; 42 for (;;) { 43 while (*val == ' ') val++; /* skip spaces */ 44 if (*val == 0) return(r); /* the proper exit point */ 45 if (*fmt == 0) break; /* too many values */ 46 47 if (strchr(PUNCT, *val) != NULL) { 48 /* Time to go to the next field. */ 49 if (strchr(PUNCT, *fmt) != NULL) i++; 50 if (*fmt++ == *val) val++; 51 if (*fmt < 32) fmt -= *fmt; /* step back? */ 52 } else { 53 /* Environment contains a value, get it. */ 54 switch (*fmt) { 55 case '*': radix = -1; break; 56 case 'd': radix = 10; break; 57 case 'o': radix = 010; break; 58 case 'x': radix = 0x10; break; 59 case 'c': radix = 0; break; 60 default: goto badenv; 61 } 62 63 if (radix < 0) { 64 /* Skip. */ 65 while (strchr(PUNCT, *val) == NULL) val++; 66 continue; 67 } else { 68 /* A number. */ 69 newpar = strtol(val, &end, radix); 70 71 if (end == val) break; /* not a number */ 72 val = end; 73 } 74 75 if (i == field) { 76 /* The field requested. */ 77 if (newpar < min || newpar > max) break; 78 *param = newpar; 79 r = EP_SET; 80 } 81 } 82 } 83 badenv: 84 env_panic(env); 85 return -1; 86 } 87