수다닷컴

질문 제목 : 질문 내용 :

readln: return-value = n, null
terminated vptr

ssize_t
readline (int fd, const void *vptr, size_t
maxlen)
{
ssize_t n, rc;
char c, *ptr;
ptr = vptr;
for (n = 1; n maxlen; n++) {
again:
if ((rc = read(fd, &c, 1)) == 1) {
*ptr++ = c;
if (c == ‘\n’)
break; // newline is stored
} else if (rc == 0) {
if (n == 1)
return (0); // eof, no data read
else
break; // eof, some data read
} else {
if (errno == eintr)
goto again;
return (-1);
} // end of for-loop
*ptr = 0; // null terminated
return (n); // return = 0
} 이게readln함수구요
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int readvn(int fd, char* bp,
size_t len) header는 length only
int readvn(int fd, char *bp, size_t len)
{
int reclen;
int rc;
// retrieve the length of the record
rc = readn(fd, (char*)&reclen, sizeof(int));
if (rc != sizeof(int)) return rc 0 ? -1 : 0;
reclen = ntohl(reclen);
if (reclen len)
{
while (reclen 0)
{
rc = readn(fd, bp, len);
if (rc != len) return rc 0 ? -1 : 0;
reclen -= len;
if (reclen len) len = reclen;
}
set_errno(emsgsize);
return -1;
}
// retrieve the record itself
rc = readn(fd, bp, reclen);
if (rc != reclen)
return rc 0 ? -1 : 0;
return rc;
} 이게 readvn함수인데요

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recvn은 해석이 쉬운데 이함수는 도무지해석이안되네요ㅠ

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