1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <time.h> 4 5 #include <cutils/properties.h> 6 7 #include <sys/atomics.h> 8 9 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_ 10 #include <sys/_system_properties.h> 11 12 13 extern prop_area *__system_property_area__; 14 15 typedef struct pwatch pwatch; 16 17 struct pwatch 18 { 19 const prop_info *pi; 20 unsigned serial; 21 }; 22 23 static pwatch watchlist[1024]; 24 25 static void announce(const prop_info *pi) 26 { 27 char name[PROP_NAME_MAX]; 28 char value[PROP_VALUE_MAX]; 29 char *x; 30 31 __system_property_read(pi, name, value); 32 33 for(x = value; *x; x++) { 34 if((*x < 32) || (*x > 127)) *x = '.'; 35 } 36 37 fprintf(stderr,"%10d %s = '%s'\n", (int) time(0), name, value); 38 } 39 40 int watchprops_main(int argc, char *argv[]) 41 { 42 prop_area *pa = __system_property_area__; 43 unsigned serial = pa->serial; 44 unsigned count = pa->count; 45 unsigned n; 46 47 if(count >= 1024) exit(1); 48 49 for(n = 0; n < count; n++) { 50 watchlist[n].pi = __system_property_find_nth(n); 51 watchlist[n].serial = watchlist[n].pi->serial; 52 } 53 54 for(;;) { 55 do { 56 __futex_wait(&pa->serial, serial, 0); 57 } while(pa->serial == serial); 58 59 while(count < pa->count){ 60 watchlist[count].pi = __system_property_find_nth(count); 61 watchlist[count].serial = watchlist[n].pi->serial; 62 announce(watchlist[count].pi); 63 count++; 64 if(count == 1024) exit(1); 65 } 66 67 for(n = 0; n < count; n++){ 68 unsigned tmp = watchlist[n].pi->serial; 69 if(watchlist[n].serial != tmp) { 70 announce(watchlist[n].pi); 71 watchlist[n].serial = tmp; 72 } 73 } 74 } 75 return 0; 76 } 77
