quick-ls.md

$ ls -f -1

https://github.com/aidenbell/getdents/blob/master/src/getdents.c

/*

• List directories using getdents() because ls, find and Python libraries
• use readdir() which is slower (but uses getdents() underneath.
• Compile with
• ]$ gcc getdents.c -o getdents / #define _GNU_SOURCE #include <dirent.h> / Defines DT_* constants */ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <sys/stat.h> #include <sys/syscall.h>

#define handle_error(msg)
do { perror(msg); exit(EXIT_FAILURE); } while (0)

struct linux_dirent { long d_ino; off_t d_off; unsigned short d_reclen; char d_name[]; };

#define BUF_SIZE 102410245

int main(int argc, char *argv[]) { int fd, nread; char buf[BUF_SIZE]; struct linux_dirent *d; int bpos; char d_type;

fd = open(argc > 1 ? argv[1] : ".", O_RDONLY | O_DIRECTORY); if (fd == -1) handle_error("open");

for ( ; ; ) { nread = syscall(SYS_getdents, fd, buf, BUF_SIZE); if (nread == -1) handle_error("getdents");

   if (nread == 0)
       break;

   for (bpos = 0; bpos < nread;) {
       d = (struct linux_dirent *) (buf + bpos);
       d_type = *(buf + bpos + d->d_reclen - 1);
       if( d->d_ino != 0 && d_type == DT_REG ) {
          printf("%s\n", (char *)d->d_name );
       }
       bpos += d->d_reclen;
   }

}

exit(EXIT_SUCCESS); }