readdat.c

来自「用Ｃ语言编的邮件系统（毕业论文）」· C语言 代码 · 共 20 行

#include	"mail.h"

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

char *
_mail_readdat(MAIL *mail)
{
	if (lseek(mail->datfd, mail->datoff, SEEK_SET) == -1)
		err_dump("lseek error");

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

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