readdat.c

UNIX编程高级环境（第二版）的网络套接字部分的程序源码

#include    "db.h"

/* Read the current data record into the data buffer.
 * Return a pointer to the null-terminated data buffer. */

char *
_db_readdat(DB *db)
{
    if (lseek(db->datfd, db->datoff, SEEK_SET) == -1)
        err_dump("lseek error");

    if (read(db->datfd, db->datbuf, db->datlen) != db->datlen)
        err_dump("read error");
    if (db->datbuf[db->datlen - 1] != '\n')        /* sanity check */
        err_dump("missing newline");
    db->datbuf[db->datlen - 1] = 0;        /* replace newline with null */

    return(db->datbuf);        /* return pointer to data record */
}