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#include "sysutil.h"
#include <stdlib.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;
}
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