Try to remove file from page cache

dropcache.c

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


int main(int argc, char **argv)
{
    int i;
    if (argc < 2)
    {
        fprintf(stderr, "Usage: %s <file> [<files>]\n", argv[0]);
        return 1;
    }

    for (i = 1; i < argc; ++i)
    {
        const char *fname = argv[i];
        struct stat st;
        int fd = open(fname, O_RDONLY);
        if (fd < 0)
        {
            printf("Cannot open '%s': %s\n", fname, strerror(errno));
            continue;
        }
        if (fstat(fd, &st))
        {
            printf("Cannot stat() '%s': %s\n", fname, strerror(errno));
            close(fd);
            continue;
        }
        if (posix_fadvise(fd, 0, st.st_size, POSIX_FADV_DONTNEED))
        {
            printf("posix_fadvise() failed on '%s': %s\n", fname, strerror(errno));
            close(fd);
            continue;
        }
        close(fd);
    }

    return 0;
}