alloc.c

用Ｃ语言编的邮件系统（毕业论文）

#include	"mail.h"

/* Allocate & initialize a mail structure, and all the buffers it needs  */

MAIL *
_mail_alloc(int namelen)
{
	MAIL		*mail;

			/* Use calloc, to init structure to zero */
	if ( (mail = calloc(1, sizeof(MAIL))) == NULL)
		err_dump("calloc error for mail");

	mail->idxfd = mail->datfd = -1;			/* descriptors */

		/* Allocate room for the name.
		   +5 for ".idx" or ".dat" plus null at end. */

	if ( (mail->name = malloc(namelen + 5)) == NULL)
		err_dump("malloc error for name");

		/* Allocate an index buffer and a data buffer.
		   +2 for newline and null at end. */

	if ( (mail->idxbuf = malloc(IDXLEN_MAX + 2)) == NULL)
		err_dump("malloc error for index buffer");
	if ( (mail->datbuf = malloc(DATLEN_MAX + 2)) == NULL)
		err_dump("malloc error for data buffer");

	return(mail);
}