/* random-access.c (GPL)*/ /* Hironobu SUZUKI <hironobu@h2np.net> */ #include <stdio.h> #include <errno.h> #include <sys/stat.h> #include <sys/types.h> #include <fcntl.h> #include <unistd.h> #include <time.h> #include <stdlib.h> #define FAIL 0 #define SUCCESS 1 int openlog[2] = { 0, 0 }; #define MAXNUM 0x100000 void open_read_close(char *fname); int nullfd; int main(int ac, char **av) { int r; char fname[1024]; time_t t; int i; int m; if (ac != 2) { printf("%s hex-style-filename \n", av[0]); printf("ex) %s 00022300\n", av[0]); exit(1); } sscanf(av[1], "%x", &m); if (m < 1 || m > MAXNUM) { printf("out of size %d\n", m); exit(1); } time(&t); srandom((unsigned int)getpid() ^ (((unsigned int)t << 16) | (unsigned int)t >> 16)); if ((nullfd = open("/dev/null", O_WRONLY)) < 0) { perror("/dev/null"); exit(1); } /* 00/00/00/00 */ for (i = 0; i < m; i++) { r = random() % m; sprintf(fname, "00/%2.2x/%2.2x/00%2.2x%2.2x%2.2x", ((r >> 16) & 0xFF), ((r >> 8) & 0xFF), ((r >> 16) & 0xFF), ((r >> 8) & 0xFF), (r & 0xFF)); open_read_close(fname); } close(nullfd); printf("Success:\t%d\nFail:\t%d\n", openlog[SUCCESS], openlog[FAIL]); exit(0); } #define BUFS 8192 void open_read_close(char *fname) { int fd; char buf[BUFS]; int c; if ((fd = open(fname, O_RDONLY)) < 0) { openlog[FAIL]++; close(fd); return; } openlog[SUCCESS]++; while ((c = read(fd, buf, BUFS)) > 0) { if (write(nullfd, buf, c) < 0) { perror("/dev/null"); printf("Opened\t %d\nUnopend:\t%d\n", openlog[SUCCESS], openlog[FAIL]); exit(1); } } if (c < 0) { perror(fname); printf("Opened\t %d\nUnopend:\t%d\n", openlog[SUCCESS], openlog[FAIL]); exit(1); } close(fd); }