#!/usr/sbin/dtrace -qs

/* displayerrno.d -- Modified version of errno.d that displays error names */

BEGIN
{
  printf("%-4s %-6s %-10s %-10s %s\n", "UID", "PID", "Prog", "Error", "Func");

  /* Assign error names to the associative array error[] */
  error[EPERM]   = "EPERM";    /* Operation not permitted */
  error[ENOENT]  = "ENOENT";   /* No such file or directory */
  error[ESRCH]   = "ESRCH";    /* No such process */
  error[EINTR]   = "EINTR";    /* Interrupted system call */
  error[EIO]     = "EIO";      /* I/O error */
  error[ENXIO]   = "ENXIO";    /* No such device or address */
  error[E2BIG]   = "E2BIG";    /* Argument list too long */
  error[ENOEXEC] = "ENOEXEC";  /* Exec format error */
  error[EBADF]   = "EBADF";    /* Bad file number */
  error[ECHILD]  = "ECHILD";   /* No child processes */
  error[EAGAIN]  = "EAGAIN";   /* Try again or operation would block */
  error[ENOMEM]  = "ENOMEM";   /* Out of memory */
  error[EACCES]  = "EACCES";   /* Permission denied */
  error[EFAULT]  = "EFAULT";   /* Bad address */
  error[ENOTBLK] = "ENOTBLK";  /* Block device required */
  error[EBUSY]   = "EBUSY";    /* Device or resource busy */
  error[EEXIST]  = "EEXIST";   /* File exists */
  error[EXDEV]   = "EXDEV";    /* Cross-device link */
  error[ENODEV]  = "ENODEV";   /* No such device */
  error[ENOTDIR] = "ENOTDIR";  /* Not a directory */
  error[EISDIR]  = "EISDIR";   /* Is a directory */
  error[EINVAL]  = "EINVAL";   /* Invalid argument */
  error[ENFILE]  = "ENFILE";   /* File table overflow */
  error[EMFILE]  = "EMFILE";   /* Too many open files */
  error[ENOTTY]  = "ENOTTY";   /* Not a typewriter */
  error[ETXTBSY] = "ETXTBSY";  /* Text file busy */
  error[EFBIG]   = "EFBIG";    /* File too large */
  error[ENOSPC]  = "ENOSPC";   /* No space left on device */
  error[ESPIPE]  = "ESPIPE";   /* Illegal seek */
  error[EROFS]   = "EROFS";    /* Read-only file system */
  error[EMLINK]  = "EMLINK";   /* Too many links */
  error[EPIPE]   = "EPIPE";    /* Broken pipe */
  error[EDOM]    = "EDOM";     /* Math argument out of domain of func */
  error[ERANGE]  = "ERANGE";   /* Math result not representable */
}

/* Specify any syscall return probe and test that the value of errno is in range */

syscall:::return
/errno > 0 && errno <= ERANGE/
{
  printf("%-4d %-6d %-10s %-10s %s()\n", uid, pid, execname, error[errno], probefunc);
}

# chmod +x displayerrno.d
# ./displayerrno.d
UID  PID    Prog       Error      Func
500  3575   test       EACCES     open()
500  3575   test       EINTR      clock_gettime()
^C

このプログラムは、エラーの名前に加えて、エラーの性質に関する詳細情報を表示するように変更できます。