88 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include "sysutil.h"
 | |
| #include <stdlib.h>
 | |
| #include <env.h>
 | |
| #include <string.h>
 | |
| #include <minix/param.h>
 | |
| 
 | |
| 
 | |
| /*=========================================================================*
 | |
|  *				env_parse				   *
 | |
|  *=========================================================================*/
 | |
| int env_parse(const char *env, const char *fmt,
 | |
| 	int field, long *param, long min, long max)
 | |
| {
 | |
| /* Parse an environment variable setting, something like "DPETH0=300:3".
 | |
|  * Panic if the parsing fails.  Return EP_UNSET if the environment variable
 | |
|  * is not set, EP_OFF if it is set to "off", EP_ON if set to "on" or a
 | |
|  * field is left blank, or EP_SET if a field is given (return value through
 | |
|  * *param).  Punctuation may be used in the environment and format string,
 | |
|  * fields in the environment string may be empty, and punctuation may be
 | |
|  * missing to skip fields.  The format string contains characters 'd', 'o',
 | |
|  * 'x' and 'c' to indicate that 10, 8, 16, or 0 is used as the last argument
 | |
|  * to strtol().  A '*' means that a field should be skipped.  If the format
 | |
|  * string contains something like "\4" then the string is repeated 4 characters
 | |
|  * to the left.
 | |
|  */
 | |
|   char *val, *end;
 | |
|   char value[EP_BUF_SIZE];
 | |
|   char PUNCT[] = ":,;.";
 | |
|   long newpar;
 | |
|   int s, i, radix, r;
 | |
| 
 | |
|   if ((s=env_get_param(env, value, sizeof(value))) != 0) { 
 | |
|       if (s == ESRCH) return(EP_UNSET);		/* only error allowed */ 
 | |
|       printf("WARNING: env_get_param() failed in env_parse(): %d\n",s);
 | |
|       return(EP_EGETKENV);
 | |
|   }
 | |
|   val = value;
 | |
|   if (strcmp(val, "off") == 0) return(EP_OFF);
 | |
|   if (strcmp(val, "on") == 0) return(EP_ON);
 | |
| 
 | |
|   i = 0;
 | |
|   r = EP_ON;
 | |
|   for (;;) {
 | |
| 	while (*val == ' ') val++;	/* skip spaces */
 | |
| 	if (*val == 0) return(r);	/* the proper exit point */
 | |
| 	if (*fmt == 0) break;		/* too many values */
 | |
| 
 | |
| 	if (strchr(PUNCT, *val) != NULL) {
 | |
| 		/* Time to go to the next field. */
 | |
| 		if (strchr(PUNCT, *fmt) != NULL) i++;
 | |
| 		if (*fmt++ == *val) val++;
 | |
| 		if (*fmt < 32) fmt -= *fmt;	/* step back? */
 | |
| 	} else {
 | |
| 		/* Environment contains a value, get it. */
 | |
| 		switch (*fmt) {
 | |
| 		case '*':	radix =   -1;	break;
 | |
| 		case 'd':	radix =   10;	break;
 | |
| 		case 'o':	radix =  010;	break;
 | |
| 		case 'x':	radix = 0x10;	break;
 | |
| 		case 'c':	radix =    0;	break;
 | |
| 		default:	goto badenv;
 | |
| 		}
 | |
| 		
 | |
| 		if (radix < 0) {
 | |
| 			/* Skip. */
 | |
| 			while (strchr(PUNCT, *val) == NULL) val++;
 | |
| 			continue;
 | |
| 		} else {
 | |
| 			/* A number. */
 | |
| 			newpar = strtol(val, &end, radix);
 | |
| 
 | |
| 			if (end == val) break;	/* not a number */
 | |
| 			val = end;
 | |
| 		}
 | |
| 
 | |
| 		if (i == field) {
 | |
| 			/* The field requested. */
 | |
| 			if (newpar < min || newpar > max) break;
 | |
| 			*param = newpar;
 | |
| 			r = EP_SET;
 | |
| 		}
 | |
| 	}
 | |
|   }
 | |
| badenv:
 | |
|   env_panic(env);
 | |
|   return -1;
 | |
| }
 | 
