title: Prefixes in member names of a struct
body: <p>Consider </p>
  
  <pre><code>struct iovec {
     ptr_t iov_base; /* Starting address */
     size_t iov_len; /* Length in bytes */
  };
  </code></pre>
  
  <p>or</p>
  
  <pre><code>struct stat {
  dev_t     st_dev;     /* ID of device containing file */
  ino_t     st_ino;     /* inode number */
  mode_t    st_mode;    /* protection */
  nlink_t   st_nlink;   /* number of hard links */
  uid_t     st_uid;     /* user ID of owner */
  gid_t     st_gid;     /* group ID of owner */
  dev_t     st_rdev;    /* device ID (if special file) */
  off_t     st_size;    /* total size, in bytes */
  blksize_t st_blksize; /* blocksize for file system I/O */
  blkcnt_t  st_blocks;  /* number of 512B blocks allocated */
  time_t    st_atime;   /* time of last access */
  time_t    st_mtime;   /* time of last modification */
  time_t    st_ctime;   /* time of last status change */
  };
  </code></pre>
  
  <p>What's the point of prefixing those member names (<code>iov_</code>, <code>st_</code>)?</p>