libgocryptfs/contrib/getdents-debug/getdents_c/getdents.c

// See ../getdents/getdents.go for some info on why
// this exists.

#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <errno.h>
#include <string.h>

int main(int argc, char *argv[])
{
    if(argc != 2) {
        printf("Usage: %s PATH\n", argv[0]);
        printf("Run getdents(2) on PATH in a 100ms loop\n");
        exit(1);
    }

    const char *path = argv[1];

    for (int i = 1 ; ; i ++ ) {
        int fd = open(path, O_RDONLY);
        if (fd == -1) {
            printf("%3d: open: %s\n", i, strerror(errno));
            if(errno == EINTR) {
                continue;
            }
            exit(1);
        }

        char tmp[10000];
        int sum = 0;
        printf("%3d: getdents64: ", i);
        for ( ; ; ) {
            errno = 0;
            int n = syscall(SYS_getdents64, fd, tmp, sizeof(tmp));
            printf("n=%d; ", n);
            if (n <= 0) {
                printf("errno=%d total %d bytes\n", errno, sum);
                if (n < 0) {
                    exit(1);
                }
                break;
            }
            sum += n;
        }
        close(fd);
        usleep(100000);
    }
}