1 /* random-access.c (GPL)*/ 2 /* Hironobu SUZUKI <hironobu (at) h2np.net> */ 3 #include <stdio.h> 4 #include <errno.h> 5 #include <sys/stat.h> 6 #include <sys/types.h> 7 #include <fcntl.h> 8 #include <unistd.h> 9 #include <time.h> 10 #include <stdlib.h> 11 #define FAIL 0 12 #define SUCCESS 1 13 14 int openlog[2] = { 0, 0 }; 15 16 #define MAXNUM 0x100000 17 18 void open_read_close(char *fname); 19 20 int nullfd; 21 22 int main(int ac, char **av) 23 { 24 int r; 25 char fname[1024]; 26 time_t t; 27 int i; 28 int m; 29 30 if (ac != 2) { 31 printf("%s hex-style-filename \n", av[0]); 32 printf("ex) %s 00022300\n", av[0]); 33 exit(1); 34 } 35 sscanf(av[1], "%x", &m); 36 if (m < 1 || m > MAXNUM) { 37 printf("out of size %d\n", m); 38 exit(1); 39 } 40 41 time(&t); 42 srandom((unsigned int)getpid() ^ 43 (((unsigned int)t << 16) | (unsigned int)t >> 16)); 44 45 if ((nullfd = open("/dev/null", O_WRONLY)) < 0) { 46 perror("/dev/null"); 47 exit(1); 48 } 49 50 /* 00/00/00/00 */ 51 for (i = 0; i < m; i++) { 52 r = random() % m; 53 sprintf(fname, "00/%2.2x/%2.2x/00%2.2x%2.2x%2.2x", 54 ((r >> 16) & 0xFF), 55 ((r >> 8) & 0xFF), 56 ((r >> 16) & 0xFF), ((r >> 8) & 0xFF), (r & 0xFF)); 57 open_read_close(fname); 58 } 59 close(nullfd); 60 printf("Success:\t%d\nFail:\t%d\n", openlog[SUCCESS], openlog[FAIL]); 61 exit(0); 62 } 63 64 #define BUFS 8192 65 void open_read_close(char *fname) 66 { 67 int fd; 68 char buf[BUFS]; 69 int c; 70 71 if ((fd = open(fname, O_RDONLY)) < 0) { 72 openlog[FAIL]++; 73 close(fd); 74 return; 75 } 76 openlog[SUCCESS]++; 77 while ((c = read(fd, buf, BUFS)) > 0) { 78 if (write(nullfd, buf, c) < 0) { 79 perror("/dev/null"); 80 printf("Opened\t %d\nUnopend:\t%d\n", openlog[SUCCESS], 81 openlog[FAIL]); 82 exit(1); 83 } 84 } 85 if (c < 0) { 86 perror(fname); 87 printf("Opened\t %d\nUnopend:\t%d\n", openlog[SUCCESS], 88 openlog[FAIL]); 89 exit(1); 90 } 91 close(fd); 92 } 93
